I really do love this game. The only problem I ever remember having in both my playthroughs (had to try out both chars!) was a glitch where I just walked off the ground and moved endlessly in a single direction. I don't know what triggered it, but it sucked because I was two enemies away from finishing Hard for Act II, Level 6. My character just walked.. and walked.. and walked, off the play area and onto the background, which I now know continues endlessly offscreen. Other than that, this game is amazing.