I just published a very small browser-based mechanics test called Alarm Line.

You start at S and must escape through X or Y within 8 moves. Every corridor you use locks behind you, so grabbing more value can remove an escape option you may need later.

It is free, requires no account, and is intentionally tiny - one map and one short ruleset.

Play here:

https://productfactory0.itch.io/alarm-line-alarm-line-micro-playtest

This is an early mechanics test rather than a finished game.