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Guillaume L.
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Guillaume L.

Unity Game Developer | Gameplay, Production & Retro Systems

I help clients turn game ideas, prototypes, and existing projects into playable, reliable systems that can be tested, improved, shipped, and maintained. My main focus is Unity game development, including gameplay programming, UI-driven game loops, mobile and WebGL builds, scoring systems, progression, player interactions, content workflows, and production-ready features. I also work on retro and low-level game development, including native C projects for Game Boy, MSX1, and Commodore 64. I work especially well on projects that need more than code implementation. I can help structure the gameplay flow, identify missing requirements, improve usability, troubleshoot technical issues, and make sure the project remains practical to maintain after delivery. What I can help with: • Gameplay systems, interactions, and core game loops • Playable prototypes, MVPs, and vertical slices • Improving, debugging, or completing existing Unity projects • UI, menus, scoring, timers, progression, feedback, and game flow • Mobile, WebGL, desktop, browser, and Linux builds • Retro game development and hardware-constrained gameplay systems • Data-driven content using JSON and CSV • Custom tools and workflows for easier content and asset updates • Bug fixing, optimization, project cleanup, and stability improvements • External service, API, and local AI integration • Controller support, device deployment, and hardware troubleshooting Alongside Unity, I have practical experience with Unreal Engine 5, Godot 4, Construct 3, C, C#, GDScript, JavaScript, Node.js, Rust, Linux, Blender, and Git. My recent independent R&D work includes developing the same retro dungeon prototype natively in C for Game Boy, MSX1, and Commodore 64, with custom sprite, palette, tile, and asset-conversion tools. I have also deployed a Godot game to an ARM64 Linux handheld and built a communication pipeline between a GB Studio ROM, a modified emulator, Node.js, and a local Ollama model. My Upwork history includes shipped mobile games, Unity ports, long-term production work, WebGL builds, prototypes, gameplay systems, and production support across desktop, mobile, and browser platforms. I work best with clients who want a practical developer who can think through both the technical implementation and the game design direction.

🇯🇵Naha, Japan$45/hr100% JSS4.93 (65)Since Jan 2008

Earnings and projects

MRR
$1.2k

Last 6 months ÷ 6

World#41,720 / 412k
🇯🇵Country#76 / 1,269
Revenue, last 30 days
$2.2k

Last 6 months: $7k

World#19,096 / 412k
🇯🇵Country#45 / 1,269
Total earnings
$72k

Billed in all: $73k

World#55,194 / 412k
🇯🇵Country#100 / 1,269
Per project
$934

$1.2k in the last 6 months

World#129,116 / 412k
🇯🇵Country#278 / 1,269
Projects, last 6 months
6
83% fixed17% hourly
World#34,405 / 412k
🇯🇵Country#87 / 1,269
Projects in all
77

Across 84 contracts

67% fixed33% hourly
World#38,397 / 412k
🇯🇵Country#70 / 1,269

Earnings, last 30 days

$73.1k+$2.2k earned in the last 30 daysBilled in all, before Upwork's fee · drag across the chart to see what was earned in any stretch
$70k$72k$74kOct 8Oct 23Nov 7

Skill rankings: Top 8% in Construct 3

Ranked by MRR among everyone on Upwork with the skill.

  1. 3Construct 338 freelancers · 🇯🇵 #1Top 8%
  2. #20Godot195 freelancers · 🇯🇵 #1Top 10%
  3. #35Game Mechanics286 freelancers · 🇯🇵 #1Top 12%
  4. #39Game Prototype325 freelancers · 🇯🇵 #1Top 12%
  5. #85Mobile Game715 freelancers · 🇯🇵 #2Top 12%
  6. #93WebGL603 freelancers · 🇯🇵 #1Top 15%
  7. #152Performance Optimization1,100 freelancers · 🇯🇵 #1Top 14%
  8. #175Game Design2,110 freelancers · 🇯🇵 #1Top 8%