Just to close this off, yes the code is on the receipt, but prepare yourself to be patient and follow the bouncing ball to get your reward! Better than paying for the game I guess but wowy.
In case you've never embarked on this magical journey, here are the general steps so you can be prepared:
1. Got to CanadaComputers redeem site and enter receipt code. That generates another code.
2. Got to AMD site. Oops... you need an account to redeem. So create new account.
3. Enter the code from CanadaComputers. Nope, you need the product verification tool to prove you are using the reward related product. Fine.
4. Download and run the product verification tool. Generates another code

5. Follow several more steps and a survey to complete the AMD portion.
6. Go over to the Relic site, the game creator, to claim with the last code. Oops... need another new account here! Create account and log in.
7. Go to Relic rewards section and enter the code. Oops... need to link Relic account to Steam. Link to Steam.
8. That generates another code!

Go over to Steam and redeem the code to get the game.
Whew! Quite the process they've come up with!