is dungeons of dredmor too hard?

Answer 1

Not even slightly.

Answer 2

It takes some skill with Roguelike and Permadeath turned on.  If you play without those, then the game can be easy.

 

In Roguelike, more monsters are generated even if you're just standing around.  If you wait in a level too long (even on the first level), you'll soon have a crowd of monsters behind closed doors waiting for you.

The game is easier or tougher depending on the skill set you choose.  Some skills require much more effort to keep alive.  Other skill combinations make you nearly invincible!