At first I'm a bit disappointed when fighting the knights doesn't feel much different. But when the dinosaur came, it became difficult and fun.
Sadly, at the level when the doctor said "my lab is doomed", I can't proceed to next level. I was chased by the dinosaurs and I try to go straight to the door thinking perhaps I have killed enough and can proceed. But nothing happened even after I killed all of them.
Overall, great game. Good job!