This article is from the Apple II Csa2 FAQ, by Jeff Hurlburt with numerous contributions by others.
You have several options: 1- Download disk images (e.g. .dsk, .nib, .2mg files) and use these as virtual disks to play the games on a PC or Mac via Apple II or Apple IIgs emulator software. Popular Apple II emulators include AppleWin and Apple Oasis. Normally disk images will be in .zip or .gz compressed form when downloaded. Use WinZip or a similar utility to uncompress these files. For more emulator references and download info, see Q&A 003 in Csa2APPLICS or (html) http://home.swbell.net/rubywand/Csa2APPLICS.html#emu . For info about disk images, see related Q&A in Csa2FLUTILS or (html)http:// home.swbell.net/rubywand/Csa2FLUTILS.html . 2- Download and uncompress the disk images of games you want to play. Then, transfer the images to your Apple II (or IIgs)-- e.g. using a NULL modem connection and either a dedicated .dsk transfer utility like ADT or a general telecom utility such as ProTerm, Modem MGR, or Spectrum. On your Apple II or IIgs the images can be converted to diskettes. Many Apple II and IIgs games are also in compressed ShrinkIt form. These may be whole-disk (.sdk) files or file archives (.shk files). Sometimes ShrinkIt files are maintained in .zip form; which means you will need to use WinZip or a similar PC/Mac utility to uncompress them to .sdk or .shk form after downloading. After transferring to your Apple II or IIgs, use 8-bit ShrinkIt or GS-ShrinkIt to uncompress the ShrinkIt file. ShrinkIt disk archives usually yield a DOS 3.3 or ProDOS disk which you boot to play a game. ShrinkIt file archives for a game usually yield one or more files and a program intended for running under ProDOS. Some file archives yield files intended for execution under a shell (such as ORCA/M) or via an interpreter (such as Frotz or one of the 'Lost Treasures' Infocom interpreters). For more about transferring files, see Csa2T1TCOM or (html) http:// home.swbell.net/rubywand/Csa2T1TCOM.html . 3- Go to a website which lets you play Apple II games on-line.