The idea suits the game jam topic well, I loved the art too! Despite the length of the tutorial, the mechanics were simple and easy to learn. I also liked it that you can use the items to gain a little control over the movement of your character.
I found the character movement a bit unpredictable while not using any items, it would be great if the player could in some way guess where the character will move. The UI might be also improved by marking the following few items you cannot choose while the black timer is active, and displaying the stats of the character (shield/damage) might also be useful to the player, but these are just some suggestions for a post-jam update, if there will be any. Anyway, the game is cool and fun, good job!