One thing that seems a bit off to me is that spells get more expensive as they go up in level. Which makes them a negative, becuase they take longer to use. So it can be a disadvantage to level them, as there's no way to choose a lower level version once you do so.
I haven't given out a 5/5 in a long time. But this game deserves it. Very robust, fun, no real flaws that I can see it in at all. I'm hoping there's a 3rd chapter. Congrats on an amazing game. :)
Level caps at 15, would take 20 to max everything out (not that it matters, you can easily beat the game long before this, even get all the challenges with just leveling the last drone)
Another bug: Sometimes you can buy a drone upgrade w/o having enough to pay for it, putting you at negative MP.