Reminds me a lot of Zelda 2 for nintendo...that one you level up in. I did find some problems with proximity issues. Some monster's center is not the center of the sprite.
I beat sparta on Why god with a fully upgraded grenade launcher and the rest of the money into a rocket turret...full missles and full firing speed. I tried the space laser and it was hard just from timing. If you feel your good with timing go for it.
 "Hero's Arms"){kind=icon}
 "Storm the House 3"){kind=icon}