The game lags when theres too many things...
...on screen, and believe me, i got a very nice computer. Also, after finishing the game, i tried again, but in the map screen the "Next" button didn't work, you should fix that =/ Though, its a fun game while it lasts.
* If you can't decide when to use a shield, or a EMP, use one when you see another pickup of them.
* When using the shields, run into the enemies, they will fall at your feet. (Or the ground, if you may. Also, obviously does not work on bosses.)
* The last gun to get, Sabobka, launches a rocket that turn into mini-rockets, though, this will not happen if it hits an enemy, launch it where there aren't any enemies, when it hits near the end of the screen, a missile mayhem appears.
* Use the guns all you can, one Ammo pickup will replenish your stock.
Good game, 7 and 4 Stars.