Just FYI I got the Itch email for this ~40mins ago and the sale had already ended, idk if my notifications settings can be changed to be faster or what.
Sorry to hear you missed the sale, itch.io can be slow in unpredictable ways. If you have a PayPal account, send an email to gravityexpressgame@gmail.com. I might be able to work something out to get you the game for the discounted price 🙂