I played around with the web version. It does seem to have a bug that the standalone does not have for me. Both Snezzy and the player's hand can leave the play area. Other than that the web version runs smoothly in Brave.
There's another glitch that both versions have where the character will flicker for a split second before changing poses. I've unpacked the game's files and I think I've got a good idea of what the problem is. RPGMaker likes to load resources only when it needs to and at the moment you're using single character sprite sheets ($ in filename). Try combining related poses into full-sized sheets so that the game loads everything all at once. Maybe a daytime animation sheet and a nighttime sheet for each character?