I know that the keyboard controls are not great, but there is not much I can do about it other than asking the player to play with the controller :D 2D Platformers are just meant to be played with a controller.
Yeah, the web build is full of bugs the windows version does not have. I have no idea why Unity is doing this... Trying to fix the bugs from the web version is a shitty task for a game jam, because the compilation takes something like 10 min during which I can do literally nothing. If we continue to work on the game, we will find the time to fix those bugs.
It's sad that you didn't get past this point. The game might be a little on the more difficult side :D You are missing some jokes, theme related dialogues and the punchline at the end.
The sfx for the checkpoint is already on the todo list + a visual indication which checkpoint is active. I might also increase the trigger area for the door so that a player always activates the checkpoint :D
Thank you very much for your feedback. I will definitely play your game this weekend. It looks really cool and people seem to like it a lot.