Reaper2k2 has ported the classic 80’s arcade & 8-bit computer game, Trailblazer, to the the Dreamcast. The aim of the game is to guide a sphere down a track, avoiding obstacles & gaps along the way. Currently the game is still buggy & does crash every now & then, you will also need a keyboard to be able to control it.
Downloads can be found at R.A.D SOft & the DCHB mirror is here. Captain Skyhawk has posted some TrailblazerDC screenshots here if you want to see it before giving it a try.