M.A.S.S. Builder
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.
- Price:$24.99
- Release Date:9/14/2025
- Franchise:Sekai Project
- Developer:Vermillion Digital
- Publisher:Sekai Project
- Last Updated:5/18/2026
- Steam App Id:956680
M.A.S.S. Builder
- Windows
- Mac
- Linux
- Steam Deck (Playable)
Steam Charts, Stats, and Live Player Count
At the moment, M.A.S.S. Builder has 30 concurrent players online and in-game. This is 83% lower than its previous all-time peak of 179 players achieved on 9/15/2025.
Review History Chart
Track historical review trends and overall ratings for M.A.S.S. Builder. It has received a total of 4,089 reviews on the Steam store and achieved a Player Score of 83 (Very Positive).
Price History Chart
Track historical price changes and trends for M.A.S.S. Builder. Right now, it costs $24.99 in the Steam Store.
Community Hub Members & Followers Chart
Explore the cumulative breakdown of Steam community hub members for M.A.S.S. Builder and its growth over time. It currently has 57,956 followers on its community page.
About M.A.S.S. Builder
M.A.S.S. Builder is a RPG, Indie, Action, Strategy, and Early Access game developed by Vermillion Digital. On 9/14/2025, it was released on the Steam Store by Sekai Project.
Players have rated M.A.S.S. Builder as "Very Positive" out of 4,089 total reviews on the Steam Store. These are split between 3,493 positive reviews and 596 negative reviews — an overall 85% positive review rating.
It is available for gamers to download and play for $24.99.
It can be played and ran on Windows systems. At the moment, it is possible to play M.A.S.S. Builder on the Steam Deck but some functionaliy may not be fully supported.
It also supports 5 languanges in-game including English, Japanese, Chinese (Simplified), Thai, and Chinese (Traditional). Each language comes with varying levels of support for the in-game interface, audio, and fully translated subtitles.
According to Steam’s category system, M.A.S.S. Builder supports the following features:
- Family Sharing
- Steam Cloud
- Single-player
- Co-op
- Full controller support
- Online Co-op
- Multi-player
From the Steam community, M.A.S.S. Builder has been tagged with the following user tags:
- Character Customization
- Futuristic
- Hack and Slash
- Third Person
- Multiplayer
- Crowdfunded
- Beat 'em up
- Third-Person Shooter
- RPG
- Shooter
- Combat
- Mechs
- Action RPG
- Sci-fi
- Post-apocalyptic
- Indie
- Anime
- Action
- Robots
- Singleplayer
- Gun Customization
Media & Sceenshots
Watch the featured video for M.A.S.S. Builder and see the latest screenshots from the Steam Store.
DLC & Related Apps
M.A.S.S. Builder is referenced by 1 other related app in the Steam Store.
| Image | Name | Type | Release Date | Actions |
|---|---|---|---|---|
 | M.A.S.S. Builder Soundtrack | Music | 5/1/2026 | View |
Related Packages
M.A.S.S. Builder is referenced by 1 package in the Steam Store.
| Name | Price | Actions |
|---|---|---|
| M.A.S.S. Builder | $24.99 | View |
Supported Languages
M.A.S.S. Builder is available in 5 different languages with varying levels of support for the in-game interface, audio, and fully translated subtitles.
| Name | Interface | Audio | Subtitles |
|---|---|---|---|
| English | Yes | No | Yes |
| Japanese | Yes | No | Yes |
| Chinese (Simplified) | Yes | No | No |
| Thai | Yes | No | No |
| Chinese (Traditional) | Yes | No | No |
Frequently Asked Questions
Soures & References
Steambase has best-in-class data powered directly by Steam, our data partners, and in-house experts. Data is enriched, cleansed, verified, and updated in realtime to ensure we surface the most up-to-date information. Learn more about the Steambase approach to data collection.
M.A.S.S. Builder data has been sourced from:
- Valve Corporation. (2026, May 18). M.A.S.S. Builder on Steam. Steam Store. https://store.steampowered.com/app/956680
- Valve Corporation. (2026, May 18). M.A.S.S. Builder. Steam Community Hub. https://steamcommunity.com/app/956680
- Vermillion Digital. (2023, July 10). M.A.S.S. Builder. M.A.S.S. Builder. http://www.v-dgt.com/