Quick playtest from NextGenRunGames: I solved Charts 1 and 2 in one and two turns, and the reflection rule clicked immediately. Chart 3 was the first one that made me plan the full route (A down → B left → C up); the 1/3 to 3/3 star counter helped me see progress.
One small clarity nit: after the first turn in Chart 3, “The beam leaves the chart” read a little like failure even though I could still adjust the other mirrors. Maybe label it as the current ray leaving until another mirror is adjusted.
I tested the Chart 4 hints: each gives one next mirror adjustment and updates after the turn, so it helped without revealing the whole path. That felt well judged so far. I stopped partway through Chart 4, so I can’t comment on later difficulty. Thanks for sharing the prototype!
— NextGenRunGames