Looks like you've got some catching up to do. Don't worry, we're here to help. Here's a bunch of free old computer games. All really tiny fast downloads. You just need to install DOSBox to be able to emulate them all.
http://www.bestoldgames.net/eng/action.php
I highly recommend Another World, Blackthorne, Flashback, the original Prince of Persia, the original GTA, Lemmings, Civilization 1 and/or 2, Populous, X-COM, and StarCraft. All should be free and legal but StarCraft, which should cost $5 or $10 tops these days. I think the whole Battle Chest is $20.
The Commander Keen games are good platforming by id before they got into Wolfenstein and Doom and whatnot. The first game is 161 KB, hahaha.
Oh, but don't get X-COM 1 from that site: it's a European version in some crazy language. The X-COM: Terror From the Deep is in English. You can find the first one in English at tons of other sites.