I've fixed the bug you encountered (if the player entered a fight on the same turn that the transformation progressed, the fight was triggered twice, once before and once after the transformation), plus, LynxSnowCat added a bunch of extra QoL features, like the ability to move with buttons in the sidebar!
I also updated the wording of the shop to make the sword/armor part of the walkthrough less different between the Python and HTML versions of the game.