This is so kickass that I feel a little awkward giving feedback, but the things that struck me are:
Using a drift mechanic in a flight sim game is simply insane! (Physics be damned!) That seems like it could really be exploited to make for some remarkable gameplay, but with a very open level design it's not really necessary to drift for maneuverability. It would take some serious thinking about how to set up a level so drifting well would be rewarded, without making the level so tight and cramped that you can't see where you're going and what you're doing when you're flying around at a few hundred miles an hour. (Maybe there are areas in this stage where it's useful, but I didn't recognize them.)
Mouse buttons for firing and slashing seem a little weird if the mouse doesn't also aim -- it seemed like aiming was determined more by which direction in world space the plane is pointing, plus some degree of auto-locking on targets. If the mouse is only used for free-look angling, when I did that it became ridiculously difficult to play so it seems like I wouldn't really use it in practice while playing. (Maybe just have a button for rearview for when I've got bogies shooting me from behind?) And in that case, I'd probably rather have my right hand on the keyboard (with access to a bunch of keys) instead of essentially just using that hand to control the two mouse buttons.
For laser fire, I might recommend either making an overheating mechanic or smth to make it more than a matter of just holding down the fire button for the entire stage, or just make it autofire instead of even needing a fire button. I'm not sure what the slash will ultimately be used for (hacking a path through obstacles?) but I didn't have much use for it in this level. Similar for barrel rolls, and braking if there's a drift mechanic. Hopefully level design will bring them into play as helpful features.
Overall the recurring theme seems to be level design. With this level, many of the gameplay features seemed not to be necessary, and ultimately in order to reach its full potential I get the feeling that level design will have to be done in such a way to demand that the players master the tools you've given them. Especially drifting :3