"Sandbox" Mode.

[H4yw1r3]

I just really ran out of ideas. One of the reason I haven't played with CL for a while.

[Petter]

The challenges that unlock new cells are designed to only require the most basic usage of earlier unlocked cell types. I've considered having a way to unlock them all without completing challenges but figured that if one can not solve the challenges one would not be able to enjoy the different cell types anyway. That would just lead to a different kind of disappointment in not being able to use the cells. I figured this way one is forced to learn how they work and one has to focus ones attention to one new cell type at a time in a systematic way, hopefully learning how they work and unlocking new cells.