I like it, but this premise isn't too original.
The first thing that struck me upon opening this game was that the character artwork didn't seem too impressive, however looking around the fill for the scenery definitely gave me good vibes, with a nice calming look and later on little subtle details like small pairs of eyes in the walls and such that I believe gave a nice ambience to the visuals. One thing regarding them that I wasn't too keen on was the absolute lack of player animation. I know as a blob kind of thing, it's pretty difficult to make an animation, but the fact that there's just nothing wasn't good for my first impressions. It struck me that you're likely a programmer and that animation may not be your forte, and if so then perhaps collaborating with one of the countless great artists this site has to offer could be a good idea. You're certainly not half bad with stationary art, however, so this may not be a fair conclusion to come to.
It sounds slightly odd, but one qualm I have with the flash is that the UI feels a bit too... 'floaty' for my preferences. I have no suggestions as to how you could improve this, but it's something I noticed and now I'm not quite able to put properly into words. There's a lot of transparency going on and the buttons don't, to me, feel like buttons. I won't elaborate further on this as my thoughts are jumbled as to how to put it across properly, but make sense of this if you will and I will be thankful.
Out of the audio the menu theme, although barely audible due to how quiet it is, and very short, was my favourite piece. It gives a sense of tension and makes it feel as if an important event is brewing and coming nearer and nearer. The in-game music is definitely very different in that it's far more energetic and I think this fits the lighter side of the game eluded to in the character art and such, as opposed to the darker feeling the background art gave me, which reminded me of the third instalment in the DooM series somewhat in the darker sci-fi sort of area.
This clash of two different themes: the vivacious one given off by the in-game theme and character artwork against the slightly creepier and tenser atmosphere of the backgrounds and menu theme, to me detracts slightly from the overall experience. It feels rather mismatched and muddled, where at any given moment you're receiving both of them at the same time.
The concept of a platformer that swaps gravity around has been around for a while, with my own first experience being the Shift games, which I wasn't ever particularly fond of, although they were rather fun. Since then, I have seen it done over and over again. I think that you carried it off pretty well, although as I said, the fact that it has been done to death in the past reduces the score for unoriginality.
Last but not least, I'm going to come onto the gameplay. The first thing that struck me was the left and right movement feeling rather bloated and sluggish, and sure, perhaps that fits the whole space theme of the game, but I believe that slightly speedier movement would be an asset. As I previously mentioned, the idea of a gravity-switching platformer has been done often in the past, however one thing that I haven't noticed in other people's flashes (not to say it doesn't exist)is the ability to swap in the air, which was present in this. This is what I believe causes this submission to stand out slightly from the rest, albeit not much. In my experience with it, it allowed for more tactics and some levels were even based on getting the balance of each one in mid-air perfect, which definitely took advantage of it.
Overall, I did quite enjoy playing this, although admittedly it didn't captivate my interest for too long, possibly as I've played so many similar games. I really liked the soundtrack, however at any given moment the audio and art direction for particular objects seemed to be giving conflicting ambience out. The movement was slightly sluggish, but I can look past that.
7/10. 3/5. I definitely enjoyed playing this, and hope that you expand on this formula further in future.