Progress: adding player sprite and starting to cut holes in the collision mesh

Unity’s various animation systems all seem to be a bit complex for what I want to do now, so adapted some simple animation code from this gamasutra article to get quick animations working.

Performance is a bit of a problem: ended up splitting the map mesh into 200x200 chunks so that an explosion didn’t have to recreate the entire thing. Performance still isn’t great - will probably have to investigate that some more later.

Here’s a later version, with some explosion animations: