Play Alien Games on Emulator Online. We have the best Alien games online for different retro emulators including GBA, Game Boy, SNES, Nintendo and Sega. There are over 27 online Alien games in our collection. All of the games that you see here are without download, pick any and start playing right away. If you enjoy the game, be sure to vote for it and leave a comment. Alien games that started it all back in the day are now playable free within your browser! Start by playing some of our popular Alien online games like Ben 10 Ultimate Alien: Cosmic Destruction, Contra 3: The Alien Wars, Ben 10 Alien Force: Vilgax Attacks and Ben 10: Alien Force.