Overload, a few Challenge arenas

Overload on Linux Mint 17.3.
Trying out a few arenas in Challenge Mode.
Overload can be purchased with no DRM for Windows, Mac, and Linux at gog.com:
https://www.gog.com/game/overload
Overload can be purchased with no DRM & Steam key for Windows, Mac, and Linux at Humble Store:
https://www.humblebundle.com/store/overload