Mossmouth, LLC
Mossmouth, LLC is a privately held, bootstrapped independent game studio founded by Derek Yu in 2009 that develops the Spelunky roguelike franchise and UFO 50, distributing through Steam, Nintendo, PlayStation, and Xbox for indie game enthusiasts and multiplayer gaming groups globally.
- Company typePrivate
- Founded2009
- HeadquartersSan Francisco, United States
- Headcount1–10
- GTM typeB2C
- OfferingSoftware
What Mossmouth, LLC does
Mossmouth, LLC is a privately held, bootstrapped independent game studio founded by Derek Yu in 2009 in San Francisco. It operates as a one-person founder studio supported by trusted long-term collaborators, including BlitWorks for programming, Eirik Suhrke for music and sound, and Lollipop Robot for QA. The studio's core catalogue is the Spelunky franchise, beginning with Spelunky Classic (2008/2009 freeware, built in GameMaker), the Spelunky HD remake (2012, Xbox 360 and later PC/PlayStation), Spelunky 2 (2020, priced at $19.99 USD), and the more recent UFO 50 (2024), a 50-game retro anthology developed with collaborators. Game design centers on procedural level generation, dynamic liquid physics, multi-layered worlds, and skill-based emergent gameplay, with Spelunky 2 adding up to four-player local and online multiplayer plus a persistent Base Camp progression system.
Mossmouth monetizes primarily through one-time digital game sales on Steam, Nintendo eShop, PlayStation Store, and Xbox (including Xbox Game Pass), with secondary revenue from licensed merchandise (Fangamer retail line, Youtooz plush collaborations) and IP crossovers (Guy Spelunky in Fraymakers, Spelunky content in Fall Guys Season 5, and appearances in Amazon's Secret Level). The studio serves indie game enthusiasts, multiplayer gaming groups, and retro gaming fans globally. It has no external funding, no subsidiaries, and no enterprise customers; its primary assets are the registered SPELUNKY and MOSSMOUTH trademarks, an accumulated body of industry awards (PC Gamer Top 100 #35 in 2025, Dope Indie Hall of Fame 2025, NY Game Awards Best Indie 2025, IndieCade Trailblazer 2020, Eurogamer and Polygon Games of the Decade 2019), and an active Discord, speedrunning, and modding community ecosystem.
Mossmouth, LLC firmographics
Firmographics- Name
- Mossmouth, LLC
- Legal name
- Mossmouth, LLC
- Website
- https://mossmouth.com
- Company type
- Private
- Founded year
- 2009
- Operating status
- Operating
- Headcount range
- 1–10 employees
- Short description
- Mossmouth, LLC is a privately held, bootstrapped independent game studio founded by Derek Yu in 2009 that develops the Spelunky roguelike franchise and UFO 50, distributing through Steam, Nintendo, PlayStation, and Xbox for indie game enthusiasts and multiplayer gaming groups globally.
- Ownership category
- akta.pro rank
Mossmouth, LLC industry classification
Industry- Product category
- Indie Video Games
- NAICS
- Software Publishers (51321)
- akta.pro primary industry
- Indie Game Studios (MPAFAAAC)
Keywords
Where Mossmouth, LLC is headquartered
LocationHeadquarters
- HQ city
- San Francisco
- HQ country
- United States
- HQ region
- North America
Markets served
Mossmouth, LLC business model
Business model- GTM type
- B2C
- Offering type
- Software
- Cost components
- Personnel, Technology or R&D, Operations, Marketing or Sales, Infrastructure
Revenue model
- Game Sales (Digital): One-time purchase revenue from selling video games directly through digital storefronts (Steam, Nintendo eShop, PlayStation Store, Xbox). Price point for Spelunky 2 is $19.99 USD.
- Merchandise Sales: Revenue from branded merchandise including plush toys (Youtooz collaboration), clothing, and collectibles sold through partners like Fangamer
- Licensing and Crossovers: Characters and IP licensed for appearances in other games (Fraymakers, Fall Guys Season 5) and media (Secret Level)
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| One time/ perpetual license | Pay-as-you-go | Standard Digital Edition |
| One time/ perpetual license | Pay-as-you-go | UFO 50 Collection |
Go-to-market motion3 records
Distribution channels7 records
Marketing channels7 records
Mossmouth, LLC product offering
Product offeringCore offering
Mossmouth develops and publishes indie video games, primarily the Spelunky roguelike platformer franchise and UFO 50, a 2024 anthology of 50 retro-style games. The studio creates procedurally generated games with tight controls and emergent multiplayer gameplay, distributed digitally through Steam, Nintendo Switch, PlayStation, and Xbox, alongside branded merchandise sold through partners.
Product overview
Mossmouth, LLC is a small independent game studio founded by Derek Yu in 2009 as a one-person studio. The company's core product portfolio centers on the Spelunky franchise, comprising Spelunky Classic (2008, freeware), Spelunky HD (2012, Xbox 360/PC/PlayStation), Spelunky 2 (2020, multi-platform sequel with expanded world and multiplayer), and UFO 50 (2024, a collection of 50 retro-style games). The studio collaborates with external partners for programming (BlitWorks), QA (Lollipop Robot), and music/sound (Eirik Suhrke), and distributes games through major platforms including Steam, Nintendo Switch, PlayStation, and Xbox.
Differentiator
Problem solved
Functional benefit
Brands
- Spelunky: The original roguelike platformer franchise created by Derek Yu, including Spelunky Classic (2009), Spelunky HD (2012), and Spelunky 2 (2020)
- UFO 50
Products and services
- UFO 50 A collection of 50 retro-inspired games developed by Derek Yu and collaborators, presented as a multi-game anthology. Released on Steam and Nintendo Switch, it is targeted at indie game enthusiasts who appreciate classic and retro-style game design.
- Spelunky 2 Roguelike platformer sequel featuring an expanded procedural world with branching paths, multi-layered levels, up to 4-player local and online multiplayer, a Base Camp community system, dynamic liquid physics, tamed mounts, and competitive Arena modes. Targeted at individual gamers and multiplayer groups.
- Spelunky (HD Remake) HD remaster of the original Spelunky with new graphics, design refinements, and music. A roguelike platformer with randomized levels and challenging gameplay originally released on Xbox 360 and later expanded to PC and PlayStation platforms.
- Spelunky Classic The original freeware roguelike platformer, created in GameMaker and released in 2008 as the foundational title of the Spelunky series. Targeted at retro gaming fans and indie game enthusiasts.
Quantifiable outcome
- PC Gamer Game of the Year 2013
- +3 more outcomes
Companies that use Mossmouth, LLC
Customer profileSegments3 records
Ideal customer profiles2 records
Mossmouth, LLC technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature5 records
Mossmouth, LLC partnerships and signals
Strategic signalPartnerships
Seven partnerships are on record, tiered minor and core.
- YoutoozminorYoutooz produces officially licensed collectible plush merchandise featuring Spelunky characters, such as the Ana Spelunky Youtooz Plush available for pre-order
- 8-4minor8-4 provided localization services for Spelunky and Spelunky 2 in Korea and Japan, enabling proper regional release with full Japanese localization at spelunky.jp
- BlitWorkscoreBlitWorks partnered with Derek Yu as the programming team for Spelunky 2, building on their previous work porting the original Spelunky to PlayStation platforms. They are listed as the primary press contact for Spelunky 2 inquiries.
- FangamerminorFangamer serves as the primary retailer for Mossmouth branded merchandise including the Fangamer UFO 50 Collection and Spelunky merchandise
- Lollipop RobotminorQuality assurance testing partner for Spelunky 2
- Fall Guys (Mediatonic)minorSpelunky collaboration in Fall Guys Season 5, featuring Spelunky-themed content and costumes in the battle royale game
- FraymakersminorGuy Spelunky appears as a playable character in Fraymakers, the indie game crossover platform fighter
Scale indicators4 records
Recent moves6 records
Expansion highlights5 records
Mossmouth, LLC competitors and assessment
Company assessmentDirect peers
- EXOK Games: Matt Thorson's indie studio behind Celeste and TowerFall — directly comparable to Mossmouth's tight, mechanically excellent indie platformers produced by a small team with strong community engagement and critical acclaim.
- Team Cherry: Independent studio behind Hollow Knight — comparable small-team indie developer of critically acclaimed 2D platformers with deep community engagement and multi-platform releases across console and PC storefronts.
- Yacht Club Games: Independent studio behind Shovel Knight — operates in the same indie platformer space with retro-inspired aesthetics, small team, Kickstarter heritage, and multi-platform releases that overlap with Mossmouth's audience and approach.
- The Behemoth: Independent studio behind Castle Crashers and BattleBlock Theater — comparable as a small indie developer of retro-styled, mechanically rich games with strong community identity and merchandise programs run through partners like Fangamer.
- Mega Crit Games: Independent studio behind Slay the Spire — a comparable small indie studio operating in the roguelike genre with breakout hit IP, multi-platform distribution, and devoted community, similar in scale and production cadence to Mossmouth.
- Supergiant Games: Independent studio behind Hades, Bastion, and Transistor — operates as a similarly sized indie studio with strong narrative roguelike expertise, multi-platform distribution, and award-winning reputation, making it the closest comparable to Mossmouth's craft-driven model.
- Edmund McMillen: Solo/duo indie developer behind The Binding of Isaac and Super Meat Boy — directly comparable to Mossmouth as a small-team creator of influential roguelike platformers with lasting cultural impact and personal-branding-led marketing.
- ConcernedApe: Solo developer of Stardew Valley — directly comparable as a single-creator indie developer who built a beloved, multi-platform franchise with merchandise, sustained relevance over a decade, and a small personal studio structure.
- Re-Logic: Independent developer behind Terraria — long-running, small-team indie studio that has sustained a beloved franchise over many years, with a similar ethos of founder-led, bootstrap-style operation and continuous content support.
Broad incumbents
- Devolver Digital: Major indie publisher that works with many studios producing the same kinds of roguelike and retro-inspired games as Mossmouth — represents the broader incumbent ecosystem Mossmouth operates within and is often compared against commercially.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat5 records
Key risks6 records
Key highlights6 records
Customer concentration
Mossmouth, LLC social profiles
Digital presenceMossmouth, LLC financial estimates
Financial estimateRevenue estimate
Valuation estimate
Mossmouth, LLC leadership team
Management profileNumber of profiles
Profiles1 record
Mossmouth, LLC funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Mossmouth, LLC M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Mossmouth, LLC
What does Mossmouth, LLC do?
Mossmouth develops and publishes indie video games, primarily the Spelunky roguelike platformer franchise and UFO 50, a 2024 anthology of 50 retro-style games. The studio creates procedurally generated games with tight controls and emergent multiplayer gameplay, distributed digitally through Steam, Nintendo Switch, PlayStation, and Xbox, alongside branded merchandise sold through partners.
Is Mossmouth, LLC a public or private company?
Mossmouth, LLC is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was Mossmouth, LLC founded?
Mossmouth, LLC was founded in 2009. It employs 1 to 10 people.
Where is Mossmouth, LLC based?
Mossmouth, LLC is headquartered in San Francisco, United States, in the North America region.
How does Mossmouth, LLC make money?
Three revenue lines are on record. Game Sales (Digital) is the primary driver. The others are merchandise Sales and licensing and Crossovers.
Who are Mossmouth, LLC's main competitors?
Direct peers on record are EXOK Games, Team Cherry, Yacht Club Games, The Behemoth, Mega Crit Games, Supergiant Games, Edmund McMillen, ConcernedApe and Re-Logic. Devolver Digital is listed as a broad incumbent.
Does Mossmouth, LLC have an API?
No public API is recorded for Mossmouth, LLC.
What industry is Mossmouth, LLC in?
Mossmouth, LLC's product category is Indie Video Games. Its primary akta.pro industry code is MPAFAAAC, Indie Game Studios. Its NAICS code is 51321.