![[PC / MAC] Door Kickers (Single Player, DRM-Free) $2.99 USD (~$3.95 AUD) @ GOG](https://files.ozbargain.com.au/n/24/375424.jpg?h=a5a1a181)
I picked this up from a previous deal and thought it was okay. A bit like a SWAT-themed version of Frozen Synapse for those familiar with that, except you also have the option to just control everyone in real time.
It appears to be available for Windows, Linux, and Mac systems.
About: Door Kickers is an innovative real-time strategy game that puts you in charge of a SWAT team and lets you command them during a tactical intervention. Analyze the situation, plan team routes, choose equipment, breach points and coordinate multiple troopers to reach the hostage room before the bad guys get to press that trigger.
Note: according to this, multiplayer is not available on this copy of the game (but most people probably buy it for singleplayer, so not a deal breaker).
The game is reliant on the Steam framework for online capabilities. The flipside is that it's DRM free, so you can copy and paste the game on as many systems you want without the need for any 3rd party DRM hooks