C64 Classix is a compilation of a staggering more than 500 Commodore 64 games on one hybrid Windows/Mac CD-ROM.
The games aren't ports to Windows or Mac platforms, but rather they are stored in the original C64 format and can be played with WinVICE, emulation software included. The games will be loaded automatically after you click on them in a nice GUI, and you don't have to load them one by one in the emulator, which comes in handy. You can even view and read additional information on each game, such as screenshots, the manual, the year of release, the original company that coded the game, links to their web page and more.
Numerous games included have versions where you can choose unlimited lives, level skip etc. Please also note that loading time is emulated as well, but using the warp mode (alt-w) you can speed up the emulator to 1300%, speeding up loading time drastically. Pressing alt-w again makes the game run back at 100% speed again.