Cute simple game. The squirrel is cute. I understand the lack of time to make the game fully. The explosion sound is satisfying but the sprite is kinda weird. It would be fine if you do not rotate the sprite or pick an explosion sprite that is round/circular that would fit the top-down perspective.
As for enemies, they spawn instantly inside the bounds around you which can caught you by surprise if you are at the corner. There are common fixes for this: A) Spawn enemis outside around the bounds. B) Add a visual cue to notify the player that an enemy will spawn here after short delay.
Nevertheless, you did fine. Good entry.