Hey there, that was pretty good. The first thing that came to mind was while the 'reverse pad'-like thing at the start was cool and set the atmosphere well, as soon as the rest of the song came it was too forward in the mix and drowned out the other elements a bit, which could have done with being a bit more front. When it gets to the chorus (around 00:40 I mean) The pad sound seems to be a bit too 'offset', starting too late and carrying on too far into the next bar. Not that everything has to be locked to a grid but it leaves the harmony a bit ambiguous (or even a bit thin) when the guitars come in, which can actually make it sound a bit confusing.
Those are my main points, everything else is cool as a cucumber. It's a good track with good atmosphere, a kind of Coldplay/Jimmy Eat World kind of vibe to it. I can certainly imagine a vocal over this. Overall, good job.