Tower

Climb nine rows. On each row pick one tile; safe tiles take you up, a trap ends the round.

Difficulty sets tiles per row and how many are safe: easy 3 of 4, medium 2 of 3, hard 1 of 2, expert 1 of 3, master 1 of 4.

After n rows the multiplier is 0.98 × (tiles / safe)ⁿ. Cash out after any row.