Looks great but not really fond of the gameplay,
dodging the bullets and shooting the enemy is a pretty common game,
and the mechanic of only being able to shoot every now and then seems just a bit annoying,

my biggest concern would probably be that for the little ammount of shots you can get off, hitting the enemy that far away while he is moving is a bit hard. Having to do it right at the moment it gets ready or not being able to hold it for longer adds to that.

Never the less, 
Great work finishing a game with selfmade art,
Never underestimate how big of an accomplishment that can be
keep up the work

Kind of interesting idea, but difficulty just don't make it that fun. I would consider to shoot automatically after 7s, because you loose that shot anyway if you don't press the spacebar right away or let the player shoot when he wants after that 7s. 

Otherwise good job.

Pretty good idea.  Although, it's difficult to follow the enemies bullets because they're small and  seem to appear out of nowhere. It'd be nice if you could shoot more regularly too. I think it would be interesting to see this more fleshed out.