Practitioner (own blog/paper) New product (mobile game)
Solo developer builds a cross-platform tower defense game in about 30 days with Claude Code, for ~$2,755 in tokens
Julien Renaux built Thumb & Pylon, a tower defense and idle clicker for iOS and Android, from a single game design doc in about 30 days with Claude Code. It has 34 hand-authored levels, a deterministic integer-math simulation core shared with the server, and leaderboards validated by server-side re-simulation. He publishes the full token meter: 9.24B total tokens, almost all cache reads, against 17.7M output tokens.
The numbers (as reported)
| Duration | ~30 days, ~12 working sessions |
|---|---|
| Tool calls | 9,436 |
| Output tokens | 17.7M |
| Total tokens | 9.24B (8.98B cache reads) |
| Cost at API prices | ~$2,755 (~93% Claude Opus 5) |
| Levels | 34 |
Facts
- Company / subject
- Julien Renaux (independent developer)
- Tools
- Claude Code
- Codebase
- greenfield
- Work type
- New product (mobile game)
- Stack
- TypeScript, React Native, Postgres
- Published
- 2026-09-10
- Last checked
- 2026-10-19
Caveats
Cost is the pay-as-you-go API-equivalent price from ccusage, not what he paid on a subscription. He says the token counts and dollar figure come from two tools that count cache reads differently. No code size given.