You mentioned in the game comments that this is your first game, so great job on getting it out there!! Some parts are still rough (e.g., art, UI bugs), but it's very fun! The difficulty feels just right, it took me 7 or 8 tries to beat easy mode then a couple more for medium. Some suggestions:
- It'd be nice if the controls were stated somewhere in the game
- Starting the timer immediately when clicking a difficulty feels a little jarring. I might add a short countdown (3..2..1..GO) or a graphic with the controls then wait for input to start
- Add some sound effects! Even just grabbing a couple off freesound.org can go a long way to building the atmosphere of your game
Overall very good so far!