I don't get this. You upgrade stats for no real reason, and then you gain souls, which i guess are like points / resources. I don't understand what the goal is, or even how you could possibly fail if simply increasing the total number of souls is success.
Where's the physics? Needs a pause where you can retarget turrets because it's simply impossible to keep up with the computer at higher levels when it can retarget all of its turrets simultaneously. Later levels won by luck, not skill. 2/5