Sorry about that! The particles are missing from the web build and you are being hit by steam. (An intermittent hazard that is completely made out of particles). Unfortunately I can't patch in another visual indicator right now because of the Jam Voting period.
Also, regarding the download, I have gotten in touch with itch.io support since it seems to be on their end. Nothing I can do about that right now either I'm afraid. :(
Thanks for playing regardless, and sorry you ran into those issues!