Classic Retro Games
The website Classic Retro Games features hundreds of remade old-school games, available for download. You need a Windows PC to play the games on Classic Retro. You can take your pick from action games such as Bomberman, Defender, Frogger, Qbert, Robocop, Wizard of Wor and the Burger Time. Download fighting games like Yie Ar Kung Fu, Barbarian and Karate Champ. There are retro puzzle games, adventure games, Pong-style games, Tetris clones and, of course, platformers such as Donkey Kong and Sonic the Hedgehog. You can browse by games category or by original platform: Apple II, NES, Atari, Commodores Amiga and 64, MSX, ZX Spectrum and Amstrad CPC.
Classic Games Arcade
If you don't feel like dealing with downloading or aren't using a Windows PC, you can play many retro games online at the Classic Games Arcade website. Here, using Flash animation, you can play childhood favorites like Pac Man, Donkey Kong, Street Fighter, Final Fight, Contra, Centipede, Sonic, Frogger, Missile Command, Arkanoid, Metroid, Megaman, Asteroids, Galaga, Bomb Jack and Super Mario Brothers. There's no worrying about installation and compatibility. You play by simply using your keyboard.
Retro Games for Macs
If you want to download your retro games but have a Mac rather than a PC, there are some resources for you, too. The website Retro 247 has two pages of retro-style Mac games for download, as of 2009. Though not as big a selection as the games found at Classic Retro Games, you can find fun things like Metal Angel, an old school 2D shooter, and Abracadabra, an arcade-style puzzle game.
A much-larger selection can be found at the Pure Mac site. This site has clones and remakes of many of your retro favorites to download, from Centipede to Space Invaders to Breakout. And, of course, Donkey Kong, which on this site is a clone named Monkey Shines.