had that too. twice. also browser version. played yesterday. so current version. stages were the one where u have to reach the top enemy as non-purple than hurry to transform to purple and kill it. and the first stage to introduce pink barriers. dunno if there r more lvls with those as i gave up after that crash... a level select would be nice. (also to be able to select the reimu version available for the selected level before entering the level so u can easily see the different start dialogues for the lvl since restarting a level doesnt retrigger that so you miss out on alternative dialogues)
since im already doing a suggestion, lets add another one:
configurable keybinds... as a german player i have a keyboard with QWERTZ layout. so games that force the usage of X and Z are annoying as heck since the way your fingers have to be to hit those with the same hand is uncomfortable.
otherwise cute game. like the idea of switching between the reimu versions and thus have different visuals and gameplay mechanics. though the dark/eyeless reimu was a bit weird... was that added because the game was made around halloween?
EDIT: yes i forgot skipping levels with "O" is a thing...