Crystal Caves... there's a blast from the past. And Wizball - that game was like smack for kids.
http://en.wikipedia.org/wiki/Crystal_Caves
"On October 24, 2005, 3D Realms (formerly Apogee) released a maintenance patch to fix a bug in the game which set the player's computer's clock backwards 100 years after playing on Windows XP." lol.
By the way, Apogee has released a lot of their old titles for free. You can find them at 3drealms.com, in the Downloads section.