Eh, it's all right.
It seems a bit buggy, though. I don't think I was ever actually able to kill an enemy. I'd almost always bump off them and end up scrolling them off the screen. That or you start off very strong and I was just killing them all that easily.
It's also waaay too tedious to build up points to get upgrades. Considering how slowly you get points from killing monsters, the power-ups are far too expensive unless you're some sort of grind machine. Then again, since I scrolled away most of the enemies rather than straight up fighting them, it doesn't seem like it would ever be necessary to actually get power-ups in the first place.
Something that would aid the tedium is if you didn't have to go back to the wizard each time you want to start a new wave of enemies. Just have them start each time the last enemy dies. It might seem a bit frantic, but, "Oh my God, gotta get back to the safe zone, gotta get back to the safe zone!" would be better than, "All right, last monster down... back to safe zone..."
Still, the graphics are nice. The animation of the pumpkin is good. The enemies are a little meh. While they are visually varied, all of them simply try to bump into you. Still, they all look fine, in a cartoony Halloween way, which makes sense considering the theme.
Overall, I like the engine. I think it would be better applied to an adventure/ item hunting game. Make the map enormous, put up regular shops and save points, downplay combat, give us a bunch of stuff to explore in the area, it'd be pretty cool, but that's just me. Not bad, but could be better.