Ubisoft reckon you aren't enough of a man/woman/laser-equipped raptor to complete the Trials of the Blood Dragon and so will give you the full game if you beat the demo.
If you prefer your driving and riding to be a little straighter, here are some great racing games on PC.
There is a catch, if you want to own the weird 80's-fuelled dirt-bike neon fever dream: You have to complete the demo with fewer than 15 faults.
Given that Trials games have the fastest and most satisfying restart system in the business, you'll likely not realise how many times you faceplant into the Far Cry-themed environment. But if you do manage it, that's a full 30-mission game with a retail price of $15 that's waiting for you to git gud at.
Hurry though, you only have until July 31 to beat the demo and bag your copy, so maybe watching a bunch of gameplay before going in for your run might help: