Thank you all of your feedback! I am aware that stage 4 is impossible :stuck_out_tongue_closed_eyes:. The scaling of waves just was way off, causing the waves to increase in difficulty, but honestly, we just wanted to show everybody what there was for us to offer you in a short and manageable time frame. Our idea was that we wanted the boss to come in early so you could see it and not let that be a waste of production.
I totally agree that the collecting mechanic was flawed without some way of automation. I think we all wanted more planets and different type of units to place on them. We focused on the aesthetics and little details so much that we didn't see the "big picture" or how to balance it.
Again, thanks for all of your feedback! It helps to know what we need to focus more on.