I changed it, so now you will get back 50%. The other half died though. Now, this number can be tweaked in the future if it becomes very unbalanced and strong.
Since you can consistently upgrade the cells, it will give you a lot of extra units by clicking. And the buffs by killing bosses should make it even more (amount of units, exhaustion chance, unit speed generation, etc).
I hot fixed and it should be working okay. But some of the previous top floors records were lost. Huge mistake of mine, I'm really sorry.