Hey there! I tried checking out the web version of the game and got a blank screen. Unfortunately, the unity launcher also didn't work (the error I got mentioned that it needs the unity.dll to be included with it). I know how frustrating these builds can be on a time crunch, so I'm sorry to be the bearer of bad news :( .
Yeah I tried the download and I think it needs additional files other than just the .exe. For example, when I built the project for windows the target folder contained the unitycrashhandler64.exe, unityplayer.dll, [project name]Data (folder), and MonoBleedingEdge (folder). I then zipped up the target folder and that's what I uploaded to itch. But ugh, I know it's like to work forever on something only to have it crash on release!