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I used to play this game when i was a kid that was 1 player, could be 2 players. One person used the keyboard one used the mouse to move and shoot. Each level looks different as you fly around in this 2D game, and shoot other ships that shoot at you. You get pickups and upgrades as you get further for more powerful spaceship guns that shoot a larger area. At the end of each level you fight a huge boss ship. Once you kill it you move on to the next level. WHAT IS THIS GAME CALLED??!?! any ideas??
Thanks