The level select cheat for DragonHeart:

D-L-D-R-D-U  (D=down, L=left, R=right, U=up)
do this at the menu screen and you'll see all the levels pop-up

Look for a file called game cheats and experiment.
All the cheats are Up-Up-Up and then a combination of Slash, Block,
and Jab.

The most useful is uuubbb which moves your strength and endurance
meter up a notch.