I did try again, and this time it did load. The previous time I did try it a couple of times, maybe I just didn't wait long enough. I was now able to complete the first level, but the whole 'taking control' it still a bit confusing. Perhaps you could explain this better in the game.
Viewing post in Chesscourt Mission jam comments
Will do if I make a proper post-jam version. In the very limited play testing I did, it wasn't an issue, but it seems a few people have had difficulty on the first few levels. Until then, I'll explain it here:
Any character you're not controlling cannot move, and is counted as being on the other team in term of movement. If you capture a piece, your current piece will swap places with it, and you will now be controlling the piece you just captured.
(The whole swapping places thing is a bit weird, I know, but its absolutely chessessary to make good puzzles, I've tried)