you need to navigate to the game subdirectory (remember the number from the email) and download the only file present there (use download command)
I have no idea then. Maybe something with your web browser?
1. Use "Connect" program
2. Type "itch.io" without quotes as the address and connect
3. Use "Bruteforce" or "Exploit" program and wait until it finishes
4. Type "cd Games!game315" in the shell and press Enter/Return. You can use "dir" command to see what a directory contains.
5. Type "download game.html" in the shell and press Enter/Return
6. Use "Disconnect" program