Very atmospheric. The track is very intense, very mysterious, and indeed very creepy! The piano melody is very catchy (not pop song catchy, but leitmotif catchy, so you can base an entire soundtrack around it), and the way it tenses up even more at the middle, i think it could've happened at the end, for a big climax that get cut off, which would be very creepy imo.
I also wanted to say that there's no shame in using garageband - I used to think it was low level too, but it is a legitimate DAW, and you can create amazing things with it - check out the soundtrack for the game LittleBigPlanet, they say it was made using garageband, and it is downright fantastic.
Anyway, good job!