296! Yeah so the score goes up the more you clear before killing the dragon. I had 3 walls left.
*More spoilers* (see the rest of my list below)
- There's a dwarf or something you can find who takes 0 attack points but gives you 10 gold.
- Always be exploring instead of cleaning up previous areas.
- There's a 1 health wizard surrounded by 8 health gelatinous cubes, always on the edge as far as I know.