Gate Crash is all about barriers that move up and down. It's pretty easy going, and there's not much strategy to how you get through. It's largely down to timing and observation, watching which doors come down when. They all follow a consistent pattern, so it's pretty easy to judge.
The tricky part comes right at the end, with a big, slime-covered slope and a jump to the finish line blocked by more moving doors. Again, it comes down to good timing. Don't forget to turn around and run back up the hill a bit if you misjudge the doors. Lots of people slip up here, but it's not too hard to clear the gap with practice.