Cool, a jump upgrade. I'll buy that first. Wait! Now the coins are higher! No way I would have bought triple jump if I had known you were gonna make the game harder for it.
step 9 causes a memory leak. each time we make the enemy array larger, the for loop that checks if your shots hit anything takes a little but larger. if you decided to expand the game with that code, you'll start to get massive slowdown as the array reaches the ten thousands or so. any chance someone reading this can help me write a splice function to keep the array size reasonable?
reading the comments, all i see is people crying about starting upgrades from scratch each level. why? oh i know why. you want to grind level 1 until you have everything, then easy mode a mode called "hard" mode. i wish you kids had to find your way through a rogue-like in the 80s.
if i could run this game at about 10x speed with auto-sending waves, id give it a 4/5 for the semi frantic feeling. as it is, there just are not enough choices to think about while i wait for the mobs to come.
Hmm, I have to shoot the other people 10 times and they only have to shoot me once... oh i get it, its not poor balancing, you just want me to use a bunch of $ on a flash game. *thumbs down*