Hmmm, I'm not certain of what else you could do in this situation. I haven't had experience in downloading any games from itchio myself. Perhaps contacting itchio's support can help out? My apologies.
Oh, uhh...I think I can help with that. That's happened to me before, and it just seems to be a problem with my internet (to be specific ; it's shitty, really really shitty). If you can't download any other games on itch.io, try using a different network.