What kind of aliens are you looking for? Silly ones, ore serious ones?
For silly ones, you could refer to Metal Slug. Also, if I'm correct, Earthbound also features some aliens.
For serious stuff, you could look for the SciFi movie-based games, such as maybe StarWars, Alien, or something like that...
Actually, for what you seem to be going for, Metal Slug might be the best choice. Go look it up on the main site here at TSR and at http://www.metalslugsprites.net/.
BTW, sorry for my rudeness.
For silly ones, you could refer to Metal Slug. Also, if I'm correct, Earthbound also features some aliens.
For serious stuff, you could look for the SciFi movie-based games, such as maybe StarWars, Alien, or something like that...
Actually, for what you seem to be going for, Metal Slug might be the best choice. Go look it up on the main site here at TSR and at http://www.metalslugsprites.net/.
BTW, sorry for my rudeness.