AstroAvenger was the first 'shooter' game I've ever played. The game is challenging and provides hours of entertainment. After you figure out the combination of weapons, armor, and battery life then your strategy becomes paramount to winning. If you don't figure out the right combination, you can be stuck on level one for quite a long time!
This is a great game for a beginner to intermediate game player. After I figured out a fairly good strategy, winning/beating the game was easy. So I imagine a very experienced game player may "shoot" right through the levels. I'd suggest
Astro Avenger 2 [Game Download] to start with if you play this type of game routinely.