There is a nice variety of interesting enemy/obstacle types, however I could just beat the game by going down and spamming spacebar, so there unfortunately wasn't much of a challenge. Also I would suggest adding some sort of background (can be very primitive to match the rest of the game) so it's a bit clearer how you're moving across the map. I think if you make it more difficult, maybe by adding more interactions with the enemies? it can turn out very fun :D
Also my antivirus thought it was a virus :(