The challenge level is a not part of the main campaign but a side level where the objective is to survive for as long as you can!
You can set it to different difficulties which changes the maximum amount of robots, anything from 1 robot at a time to
15 at once!
the robots are randomly spawned from the 3
different classes in the game so far: saw robots, drill robots, Missile robots. I have also added alien blobs that restore your health to give you the chance to survive a bit longer.
This update took a bit longer than planned, this was because of a strange error that stopped me form exporting a standalone, I started getting this error after I upgraded unity from 4.30 to 4.52, this is the error "Fatal Error! out of memory unityEditor.HostView:OnGUI()" I had made a backup of the game before I updated Unity so I just re installed the earlier version of Unity which fixed the error.
Next I plan to add mine laying robots and stop the missile robots from shooting missiles when there are obstacles between them and you which results in the missile robots killing themselves. I also want to add local multiplier, I may do other changes but those are the ones that strike now.