DAEMON X MACHINA
Pilot your fully customizable Arsenal mech and join your fellow mercenaries in defending humanity from the corrupted machines and gigantic robots in this post-apocalyptic action game!
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M.A.S.S. Builder on Steam
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Commander, customize and build your Mechanical Assault Skeleton Suit (M.A.S.S.) and lead the fight against an alien invasion bent on exterminating the human race. The fate of humanity is in your hands.
M.A.S.S. Builder is a mechs, action rpg and character customization game
developed by Vermillion Digital
and published by Sekai Project.
Released on September 14th 2025 is available on Windows, Steam Deck and Steam Machine
in 5 languages: English, Japanese, Simplified Chinese, Thai and Traditional Chinese.
It has received 3,731 reviews of which 3,171 were positive and 560 were negative resulting in a rating of 8.2 out of 10. 😎
The game is currently priced at 17.15€ on Steam with a 30% discount, but you can find it for 3.15€ on K4G.
The Steam community has classified M.A.S.S. Builder into these genres:
Mechs
Action RPG
Character Customization
Robots
Gun Customization
Indie
Hack and Slash
Sci-fi
Anime
Shooter
Action
Singleplayer
RPG
Futuristic
Multiplayer
Third-Person Shooter
Combat
Third Person
Post-apocalyptic
Beat 'em up
Here is the detailed breakdown of supported languages for M.A.S.S. Builder:
| UI | Subtitle | Audio | |
|---|---|---|---|
| English | |||
| Simplified Chinese | |||
| Traditional Chinese | |||
| Thai | |||
| Japanese |
Media & Screenshots
Get an in-depth look at M.A.S.S. Builder through various videos and screenshots.
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System requirements
These are the minimum specifications needed to play the game. For the best experience, we recommend that you verify them.
Windows
- Requires a 64-bit processor and operating system
- OS *: Windows 7, Windows 8.1, Windows 10 (64-bit versions only)
- Processor: Intel Core i5 or better / AMD Phenom II X3 or better
- Memory: 8 GB RAM
- Graphics: NVIDIA GeForce GTX 1050 or better / AMD Radeon RX 560 or better
- Storage: 3 GB available space
- Sound Card: DirectSound Compatible
Steam Price & Best Deals
User reviews & Ratings
Explore reviews from Steam users sharing their experiences and what they love about the game.
It's a mech-builder game, and it's cheap. The combat is average; light and floaty and handles more like a dynasty warriors game. You feel more like you're playing as a some dude wear mech-flavored armor. Despite there being no advantages or disadvantages to making a cool mech, if you like making your favorite mech (Gundam, Transformers, Macross, Patlabor, Pacific Rim, etc...) you can do it here, with better results than most other games. I built a sizable number of my favorite Gundams and several personal units. They all look cool and function well. The tuning system lets your mech function in any way you want with the right parts. And while there could be more parts to really get the right look, you can get close enough with enough patience and experimentation. The game has pretty good music most of the time. Now, here comes the list of negatives. Building your mech's aesthetic armor requires lots of different shapes and parts. You don't know whether a specific part is a good fit until you buy the schematic for it and the good parts aren't cheap. As such, unless you're using the prefab set pieces you won't be playing 80% of the game's story with the mech of your dreams until you're able to farm a lot of money to buy them. The part building system is also not explained at all. Since it's vital for constructing custom-built armors, that's important. I saw a youtube video that showed someone doing it and figured it out from there. Another problem is the dialogue. The story has... good bones. But the dialogue between the characters and the pacing of the story is absolutely terrible. They need a native english speaker to translate their stuff because someone will be talking about a cat and the next message is unprompted rage. One of the engineer guys speaks with what I think is supposed to be a scottish accent, but only for the first line of his dialogue and then loses it for most of the conversation until the writer remembers that they're supposed to sound different, only to give them a completely different accent. The player character has no identity, no lines, no dialog choices and seems to be wholly useless. There's a whole lot of important information about the world, lore, characters, etc.. somewhere in the game. I found it once, then lost it. Game naming terminology is especially bad. With names like "Bullet Shooters", "Energy Shooters" and "Bullet Launchers". Which, while technically correct, are abhorrent to any native english speaker as the words of a very young child who doesn't know the right names for things. Even the title acronym M.A.S.S is... cringeworthy when you see it. Mechanical Assault Skeleton Suit. Terrible. No weapon engineer is going to give anything a name like that. It's neither a skeleton, nor a suit, are used for non-assault purposes (cargo) and isn't operated using cogs and gears. Mechanized Autonomous Strike System: One of a dozen possible permutations of M.A.S.S that don't cause profound nausea to read. The tuning system has completely unformatted upgrade descriptions. Just a stream of vague effects with no line breaks: "On hit chance to trigger X", On which hit? When I hit them? When they hit me? What's the chance? 1%? 25%? How is that useful? Then the next, completely unrelated effect from that "item" will continue on from there instead of being on a separate line. It's a mess. The enemies... aren't good. They're either easily killed or bullet sponges. The individual units don't have identifiable names, so you're going be calling them generic things like "Punchy", "Dragon" and "Teleporting bastard". "Quarks" is a terrible name for the enemy. They're made of "void particles", so just call them "VOIDs" like a normal JRPG. "Quark" is a nerdy, scientific term (or a ferengi bartender), not the name you give to the enemy of the world. Either way, combat isn't particularly satisfying. You don't feel heavy like a 700-ton mecha and enemies don't perform any sort of complex behavior... or look cool most of the time. All the melee weapons function more or less the same. Despite using various bladed weapons, spears, axes, hammers, knuckledusters, there is little to no difference to the animation and no different damage types beyond the generic "melee", bullet and plasma. The element system is underdeveloped, not explained at all, and badly implemented. It doesn't really matter since 90% of your damage is just your raw numbers; while elemental damage seems to detract your raw damage numbers and add a separate elemental damage (with no bonus to counter the obvious loss in overall numbers). Most enemies don't even have an elemental weakness, so it's moot. Despite the desire to multiclass and swing a sword, fire a gun and launch rockets from your back as all new players will want to do. You will be actively punished for doing this. Focus on one specific weapon type and put everything into that. It's not as fun, but will get you to the end. tl;dr Building a mech is great, once you know how to attach the individual parts and can afford the blueprints. If you're the creative type, you can make pretty much any mech you want. You can even pose it in a variety of backdrops and poses and take photos. Combat is flat and largely unsatisfying. There are some fun missions later on, where it's you vs waves of enemies and the clock. Multiplayer is a myth. It doesn't exist. The game's writing and naming is bad and inconsistent. The game is cheap. That's a good thing. If you get it on sale, it's definitely worth it. More than Gundam Breaker. MASS Builder could be so much better. It probably wouldn't take much more than rewriting some of the in-game text, and rebalancing a lot of the stat numbers. But... you can't do either of those.
Preface: Remember that this is a small indie company trying their hand in a fast, giant mech genre that is few and far in between. Cons: -the game has some bugs and the one that I found in particular didn't have any troubleshoot that I could find in any search engines, in here (store page,) or in their (developer's) discord. -their response time is horrid(12+ hrs with an average of 20hrs) and apparently not as bad as when they actually address game issues as they need to be identified first and then go through the process of troubleshooting -if you find yourself with an issue with no fix, CONGRATULATIONS! you've managed to discover something that needs fixing. -possibly more things that one can expect from a newly released indie game -save files and screen shots feel like playing where's waldo because they aren't located where you'd expect them. -when customizing, you will eventually end up saying, "life would be better if I had that button". a lot. usually a 'delete' button. -multiplayer doesn't seem to work (which is too bad, though I've seen multiplayer games on youtube so idk) -the game will occasionally remind you that the game requires a bit of your patience -as great as the customization is, you will eventually hit a wall and when you do, you'll be sorely disappointed. it's not game breaking but it'll leave you hoping that, "they would add it to the game in the future". -it's a very new game Pros: -this game moves more like AC1. no quickboosts or overboosts. you can move fast without (realistically) turning your yourself (the pilot) into mush inside the cockpit. if you're more into that or don't mind not having breakneck speeds, then you'll like how MASS moves. -the customization has to be the highlight of the game. I find myself losing far too much time MASS BUILDING and the more time you spend on it and discover more ways to custom your machine, the longer and more MASS you'll build (if you're into designing your machine) -even if you're not into building and would only tolerate it to recreate just about ANY character (mobile suits, armored cores, NEXTs, ranger zords, GUYVER, etc.,) you have a very powerful tool at your disposal to get very close to the desired model. -the devs have their own discord and will eventually address you personally. you'll have to remember that they live in south east Asia and is a small dev team so if you're expecting a quick chat at your whims, you'll just get annoyed (ask me how I know). they are trying and I appreciate the effort. -it's a very new game How the game feels: -machine speed falls somewhere between the realism of Battletech/Mech Warrior/Mech Commander(typically tops at 150mph) and a flight simulator using a slower moving aircraft (ave 300-350mph) without any sudden, short boost of speed that exceeds normal function of the boosters, lending to a more fluid, flat speed combat -combat honestly feels more like a beat em up. you can construct a machine with a varying distribution of your armour's weight (which will affect your speed), fire power (lighter weapons are faster, heavier weapons hit harder. the amount of resourcers that they consume also reflects their singular hit potential. all of that are enhanced by how you've distributed your 'talent points' which is based on the three major facets of your machine that will ultimately determine how the machine ends up playing. basically, you can specifically target attributes to make the machine play in a way that YOU would personally find fun. other features: -you have plenty of space to make plenty of builds. -photograph mode allows you to showcase your the MASS you've constructed to do up to 40 poses (if I remember correctly) and to one of the many different backdrops. as far as I know, this is unique to this game only (if we're talking about games of the genre.) let's be honest now, you didn't spend all those hours painstakingly constructing your machine only to see one side of your of it on the cutscene and mostly just it's back during gameplay. you are determined to recreate, "that pose" from, "that anime/manga/show/movie"... whatever might that be. every piece you've resized, reshaped, and put in place is a step closer to a wicked drip screenshot. it'll be your desktop wallpaper. -you can report suggestions or bugs directly to the devs via their discord Personal Review: Needs the addition of the following- -OB and QB -Customization: to be able to re-set the default attachment for base parts -Customization: reverse legs -Customization: weapon arms -Customization: specified hand/weapon use -Customization: reverse legs (though you can effectively make them from biped with some creativity) -Customization: to be able to link cosmetic weapon parts (minigun barrles, thrusters, etc.,) to appropriate parts -Customization: to not have to rely to base template weapon parts -Multiplayer needs fixing (Might just be me, not really sure)
This is a good game. But it is just not popular. This title has done something that many other titles failed to do. Give you access to a great deal of customization that allows you to create fan made versions of mecha from popular media, be it animated or just drawn. You can also create the weaponry for these mecha and you can use them all to fight enemies in the world of the game. The combat for this game is its biggest negative, as the movement of the mecha fells as heavy as it should but also looks a bit too clunky. Enemies who are hit with attacks recover a bit too fast from your attacks making you feel that even if you land a full combo on a target, they can and often times will retaliate right after. It is for this reason boss battles feel as if they are overwhelming... even though you can complete each and every boss fight in the game with without tacking much dmg if you have a properly leveled mecha. You have ways to avoid the dmg with blocking and or dodging with your boosters but these small blemishes on the otherwise sparkling image of them game seems to be enough to keep audiences from continuing to play. That being said... the combat works fine! No fight feels totally unwinnable. No goal feels out of reach. Enemies feel as powerful as they should on the different difficulties. The Main reason reason this game did not do so well was poor promotion. Not many people know of this title in the mainstream and as such it has gone under the radar. There are cute characters left and right, a good story, great gameplay, cool customization, Interesting enemies, and with a very communicative dev team... this game should have been at the very least well known as a video game.
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Frequently Asked Questions
M.A.S.S. Builder is currently priced at 17.15€ on Steam.
Yes, M.A.S.S. Builder is currently available at a 30% discount. You can purchase it for 17.15€ on Steam.
Yes, M.A.S.S. Builder received 3,171 positive votes out of a total of 3,731 achieving a rating of 8.20.
😎
M.A.S.S. Builder was developed by Vermillion Digital and published by Sekai Project.
Yes, M.A.S.S. Builder is playable and fully supported on Windows.
No, M.A.S.S. Builder is not playable on MacOS.
No, M.A.S.S. Builder is not playable on Linux.
Yes, M.A.S.S. Builder is playable on Steam Deck, though it might require a few minor tweaks. Make sure to check the Steam store page and community feedback on ProtonDB for exact compatibility details.
Yes, M.A.S.S. Builder is playable on Steam Machine, though it might require a few minor tweaks. Make sure to check the Steam store page and community feedback on ProtonDB for exact compatibility details.
No, M.A.S.S. Builder does not support VR.
M.A.S.S. Builder offers both single-player and multi-player modes.
M.A.S.S. Builder includes Co-op mode where you can team up with friends.
Yes, there is a DLC available for M.A.S.S. Builder. Explore additional content available for M.A.S.S. Builder on Steam.
No, M.A.S.S. Builder does not support mods via Steam Workshop.
No, M.A.S.S. Builder does not support Steam Remote Play.
Yes, M.A.S.S. Builder is enabled for Steam Family Sharing. This means you can share the game with authorized users from your Steam Library, allowing them to play it on their own accounts. For more details on how the feature works, you can read the original Steam Family Sharing announcement or visit the Steam Family Sharing user guide and FAQ page.
You can find solutions or submit a support ticket by visiting the Steam Support page for M.A.S.S. Builder.
Data sources
The information presented on this page is sourced from reliable APIs to ensure accuracy and relevance. We utilize the Steam API to gather data on game details, including titles, descriptions, prices, and user reviews. This allows us to provide you with the most up-to-date information directly from the Steam platform.
Additionally, we incorporate data from the SteamSpy API, which offers insights into game sales and player statistics. This helps us present a comprehensive view of each game's popularity and performance within the gaming community.
Last Updates| Steam data | 26 September 2026 05:13 UTC |
|---|---|
| SteamSpy data | 18 October 2026 06:34 UTC |
| Steam price | 26 October 2026 19:38 UTC |
| Steam reviews | 19 October 2026 15:58 UTC |
If you'd like to dive deeper into the details about M.A.S.S. Builder, we invite you to check out a few dedicated websites that offer extensive information and insights. These platforms provide valuable data, analysis, and user-generated reports to enhance your understanding of the game and its performance.
- SteamDB - A comprehensive database of everything on Steam about M.A.S.S. Builder
- SteamCharts - Analysis of M.A.S.S. Builder concurrent players on Steam
- ProtonDB - Crowdsourced reports on Linux and Steam Deck M.A.S.S. Builder compatibility
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Game modes
Multiplayer
Features
Online players
10
Developer
Vermillion Digital
Publisher
Sekai Project
Release
14 Sep 2025
Platforms
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