To be fair, the above trailer isn't terribly creepy in and of itself. It's a fairly straightforward illustration of what gamers can expect from Sonic & Sega All-Stars Racing. That is to say, it's a kart racing game with a cast of colorful characters (and Ryo Hazuki, for some reason) and nifty power-ups. Frankly, we think most gamers can get behind the idea of transforming into Super Sonic in order to mow down the competition and win the race, so all of that is pretty acceptable.
The creepy part, you see, is the music behind the trailer. Specifically, it's a parody of the classic holiday tune, "The Twelve Days of Christmas." What's so creepy about that, you ask? We're not exactly sure. Maybe it's just how earnestly it's being sung. Watch for yourself and maybe you'll see what we mean.