Thanks for playing, english grammar in the game ins't really good, because I'm from Europe country where not everyone speak english, and our schools don't care about english that much. Also thanks for the suggestion about controlling mini enemies, I'll try to implement it soon. Now the final level is very long because it's infinite. I should say this somewhere in the game. About upgrades: I'll make upgrades more expensive, if you have some idea for prices of upgrades let me know. Thanks for the review.