Just a few more tweaks to the engine, and it'll be perfect.
First off, give the player the option to remap their path, without needing to die and go through the cutscene again. Second, if the player dies, give the option to change node placement without remapping their path. Third (though this would require a lot more effort than the first two), instead of simply saving upgrades but not unspent AP, record the AP high score for each stage and at which stages the upgrades were bought.
Different is good
But I think you should add a better tutorial.
awesome work guys
i like all the UI designs. very professional looking
the bosses are a little tough considering you don't know what they are going to do until a couple tries in, but i'm glad you put bosses in to change it up from gunning down multiple characters in the other levels etc.
the game controls very well but needs multiple attempts to learn how fast everything moves, the timing of the enemies' weapons, and the general other mechanics of the game. because i had to retry certain levels a good amount of times, it would have been useful i think to be able to have the option to restart the level more quickly.
overall it's a great idea, i think it could potentially be executed better if there were more and different kinds of levels but given the timeframe it is an excellent game. you should definitely try expanding on it with difference mechanics and attacks, along with visible projections of enemy paths (if you were to add more levels with an easier curve)
this game is fun :D