Ahh Hover, I love that game! I've been wanting to do something with it for a while, but I've obviously got a lot of other things going on right now.

As for the file you're looking at, could it be an RMI? Basically a RIFF-based MIDI format created by Microsoft (I believe the actual data is more or less the same as the standard MIDI format, just wrapped in a RIFF container).