ROM Hollow

The manual was never included.
You boot a cartridge that has forgotten how it works. You are the save file, and you want out.
There are no instructions. The manual has exactly one entry, and it says 001. PLAY.
The other 49 are recovered by playing, out of order. Every one is a real rule of the game, one you were already subject to whether you knew it or not. A player with twenty entries can see the gaps in the numbering, and the gaps are the point.
A roguelite that remembers what you learned, not what you earned
Each run takes you through five of ten sectors, each ending in a boss. You pick up Forms that change how you move and Chips that change how you play. Then you die, the cartridge resets, and you go again.
There is no experience, no currency and no permanent stat upgrade. The only thing that survives a run is knowledge, recorded in the manual. On your fortieth run you are better because you understand more, not because your numbers are bigger.
Features
A self-writing manual. 50 entries, unlocked by play, never in order.

Ten sectors, ten bosses. Each run visits five, so no two runs follow the same path.

Twelve power-ups. Four Forms that change how you move, and eight Chips with three tiers each.

Three endings. One of them you will not find by fighting.

Physics you can learn. Momentum, springs, water, conveyors, crates and wind all obey one consistent set of rules.

A Daily Boot. One seeded run per day, the same for every player.

No accounts, no online requirement, no microtransactions.

Made by one person
ROM Hollow is made by a single developer who grew up on this kind of game and wanted to make one that respects your time. It is short enough to finish a run on a lunch break and deep enough to still be finding manual entries weeks later.