This game is awesome...but does become a bit trivial once you get Ultimate Magic. To combat this, I'm going to try and beat the game (again) this time, using no skills at all, thus ensuring a continued challenge throughout!
I don't know why, but Thing Thing 4 suffers major problems at least on my PC. I have trouble with complex manoevours performable on TT3 easily, and sometimes when i fire quickly, i can't stop firing or move. This causes a lot of deaths for me, which really stinks. Good game, but it doesn't work for me.
A good way to beat Hard Mode is to get 3 hatchet men. Anytime a member of staff approaches you, hit them with all your hatchets, killing them in one turn. Once you've killed most of his staff, take the fight to the enemy candidate.