I bought it yesterday, because the U.S. price is the same as the Canadian price (and 10% off), which makes it about $12CDN cheaper than Steam. And I was pretty excited to try it, so that was all the justification I needed.
Finished the campaign yesterday, too, and it was short but I was fine with that. More importantly it was a lot of fun and I'm sure I'll be dipping back into endless mode plenty.