One thing (Just personal opinion) about clone upgrades. I understand the limit you gave them, so that people can't just play infinitely, but it seems to me that it feels a little forced. What I would do is make it so you can have infinite clones, but each one costs 2 upgrade points. That would Allow people who are happy with what upgrades they have to continue spending points, but not get a clone every level. Just a thought, and it would be cool if you'd consider it.