A few definitions for your information:

Emulators - Programs that allow your computer to run games for old console units or computer systems, such as the NES or Commodore 64.

Shareware - Games that are crippled somewhat or only contain a portion of the game. Meant to intice you into buying the full version on the game.

Freeware - Games that are not crippled in any way. Full versions of games for FREE! Sometimes old games are made this by companies to promote sequels.

Abandonware - Games that are more than 2 years old and are no longer sold, are called abandonware.

Qbasic - Games that are written in a special language and are usually small and compact. Require an interpreter to run.

Text Adventures - An old style of writing games that required no graphics, only text descriptions. Usually small and compact.

Online - Games that must, or usually are played online. This is further divided into Multiplayer & Java+Shockwave.Multiplayer games are games that are played against other human opponents online, and java & shockwave games are games that require no downloads and can be played straight from your browser.