Not Recognized - Resolved

[Aurrie]

I've been dying to play Amnesia for ages, so I decided to give the demo a go. It was awesome! I went to buy the full download a couple of days ago, but I couldn't get it to do! It'd get half way, before saying that the download was interrupted, or it would tell me that access has been denied. I finally managed to get the download to go through this afternoon, but now I can't open the file! It says that the "Following disk images couldn't be opened: amnesia_tdd_1.2.dmg not recognized."

I'm on a Mac OSX 2.4 GHz Cor 2 Duo, 2 BG 1067 MHz DDR3

Any help in rectifying this situation would be extremely appreciated! I won't lie, I'm not really computer literate and mostly only use this for photoshop/illustrator work. I've never played games on here, before, so I am new to this whole thing.

Thanks in advance!