I quite like the exploration and trying to figure out how far you can go where.  You can choose to bump your head against every wall until the wall crumbles or you can figure out where you can climb the wall, or where the hole is, or which part is destructible, or just walk along the wall until you find another wall to bang your head into.

It also got patched recently so you can just buy the beginning weapon improvement bits rather than have to hunt down mines.  I liked hunting down mines but this definitely helps if you want to experiment with a few weapons before deciding X is the one you want to rely on.