Yeah, try to clean up the scenery if you can. Smooth shade the pumpkins for example, and putting a monster as a cube isn't the best idea IMO. The tombstones are kind of thin too.
Maybe it's better to use anim8or instead for projects like these, at least that's what I'm using for my underground coaster. (OC isn't going to do the job there, lots of individual point manimpulation and connection needs to be done.)
Here's the ride's basic info:
http://www.nolimitsdevcenter.net/p2598