Thanks for the superb feedback!
The WebGL build proved to be a lot buggier than the editor version so falling out of the map problems were quite common. Also, thanks for pointing out the errors with mesh collisions, this time I was experimenting with creating my own models and using the mesh collider however due to some of the normals of my object facing the wrong way weird collision errors appeared.
Oh and I uploaded the wrong build so the timer doesn't actually make you lose, I'll have to fix all the bugs as soon as the Jam is judged.
Thanks for the suggestions too! They're really good and I'll consider it!