Higher number of AI players / computations (pretty much any campaign mission with 2 or more AI's) = an un-playably laggy game with constant freezes and stuttering.
Building rooms literally takes several seconds per tile to build.
Minions jump around on screen, I guess trying to catch up with positional information.
Forget about trying to open the game menu or use the UI, that takes around 10s to respond.
Ubuntu 14.04 LTS (64-bit)
Intel® Core™ i7 CPU 930 @ 2.80GHz × 8
GeForce GTX 960/PCIe/SSE2
8 Gb RAM
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