Delay is waay too big and it's tough to predict, where you will be moving next and how much. I'll definitely decrease the input delay and maybe add some visual indications, how much of a given direction i held or something(e.g queue of actions, so when you press and hold left arrows, it will maybe display message "Moving Left" and when pressing right "moving right". And when this action will be executed, just remove the message and put the next one on the old one and you know what I mean
And second thing: Maybe display some UI how many of these I have to enable and how many I've enabled already.
But 3 hours is not that much to make everyting polished and great, anyway, jams are great to learn and hopefully you learned a lot from making this game.