It only takes one or two runs to get the hang of all the mechanics, and once you've got that down then it's pretty easy to reach the last floor. The final boss is difficult without being irritating, but I feel like there needs to be some more difficult enemies and traps, along with a few more floors to dwindle the player's resources before they fight the final boss. I'd also suggest making the last floor a more traditional boss fight, long-ish hallway towards a boss arena with a few enemies to back up the wizard