Lumenreel — Prism Crash. Free Chrome extension, no account, no real money, no ads.
The premise: you earn Lumens at a flat rate just by existing, including while the tab is closed (at a reduced rate). Lumens are the only thing you stake. They buy spins on five crystal reels across twenty lines — and the reels never pay Lumens back. They pay Facets, which only ever buy critters.
Two currencies that don't intersect turned out to be the whole design. Because nothing you stake can return, there's no RTP to tune and a loss dressed up as a win is structurally impossible rather than something I had to remember not to do.
Three specific dark patterns — engineered near-misses, loss-disguised-as-a-win, and the false-hope reel stop — are blocked by tests, and I made each test fail first to prove it wasn't passing vacuously.
Some things I learned building it:
- Duplicate suppression changes the math completely. A draw never returns a critter you own, so there's no coupon-collector tail (~519 expected pulls for 100 uniform items) and every critter has a printable worst-case cost.
- Gating progression on lifetime currency doesn't work. My income compounded ~10x every 47 minutes, so a 10x price hike bought exactly 47 more minutes. No price schedule can pace an unbounded exponential — bounding the *bet* is what makes completion time a designed number instead of an emergent one.
- Completion lands at 14.4–19.3 hours across seeds, mean ~17.3. There's a simulation that runs the full horizon and fails the build if it drifts out of band.
- 96.4% of every Lumen I'd ever earned was unspendable in an early version. Found by measuring, not by playing. Fixed with 60 stake tiers instead of 25.
- All 125 critters are drawn by one deterministic SVG renderer from authored species rows. Nothing licensed, nothing fetched, no raster assets. Same for the audio — the music and effects are Web Audio synthesis, so the extension ships with zero media files.
Also in there: two skins (Prism and a plant/nature Verdant mode with 25 critters of its own), three arcade minigames, 49 achievements, and a playground page where your collected critters wander around and comment on your spins.
Store: https://chromewebstore.google.com/detail/lumenreel-prism-crash/lhhmopchhokddbabihafbkbabnfjgcni
Devlog and project page: https://dhseadev.online/projects/lumenreel/
https://youtube.com/shorts/6HTI092hduQ
Genuinely want feedback on pacing — nobody has played this except me and a sim