I think, the game has a great feel, it's "juicy" and kind of addicting, although i really miss the player's freedom, (which could come the way you splitted the mechanics,) to deal with each obstacle the way he wants to: i tried dodging the red projectiles, but i had to shield, because they track me through the whole game, I tried shielding the pink obstacles, but i had to shoot them, i even tried destroying them with the red projectiles that were still chasing me, but it didn't work.
These little changes could add so much replay value, maybe consider them? :) It would make the mechanics feel more versitile (but then again, i just love sandbox, and if that's not, what you want, so be it ^^) and let the player think more (and feel less like "Simon says: shoot now", if you know what I mean ;) ), while also giving a possibility of making the connections between the parts more significant (for example if you have no time to switch you need to steer through the minefield, which needs a different skill-level)
you see, I care very much for the game, and would love to see you enhance it's potential :)