Here's 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
There's some in game cheats, but I couldn't find what all
of them did. All the cheats are Up-Up-Up and then a combination
of Slash, Block, and Jab.
I think the most useful is uuubbb which moves your strength
and endurance meter up a notch.