Follow this guide to view your A Hat in Time pledge.
Verify that the pledge description includes the soundtrack, or that your pledge is at the $10 USD tier or above.
If you are not a Kickstarter backer, or if your pledge does not include game keys, then you are not eligible for a free game key. More info on how to purchase the game here.
2. Your Alpha and Beta keys upgraded to the final game
If your Kickstarter pledge was $40 USD or above, you have received the Beta Build of A Hat in Time. If you have already redeemed those keys, then congratulations, you already have the full game in your library! If not, then please find those keys. Follow step 3 for assistance with finding your game keys.
3. Check if you have received the game keys
Check your email inbox for any email from Humble Bundle or Gears for Breakfast. The emails are titled either: "Your A Hat in Time order is ready", "Hat in Time - Your BetaBuild is ready!" or "Hat in Time - Your Alpha Build is ready!". Make sure to check your spam folder as well.