Shadow Ops is go, go, go...

This is a squad-level sci-fi / cyberpunk skirmish sandbox, which can also cover near-future and 'old skool retro' settings.
Shadow Ops plays in under an hour, has only got four pages of core rules and lets you get on with having fun.
There is minimal list building, quick set up time and swift play mechanics (if one model in a unit can shoot the whole unit can shoot, if one model can be targeted the whole unit can be targeted). The units are archetypical and easy to represent with your minis -
Light Infantry, Grenadiers, Cybernetic Warriors and so on.
The book includes four different scenarios, including two
Shadow Ops - special commando missions with asymmetrical forces.
Tinker around with the engine and add whatever units you want - it is really easy to mod to your own specifications!
And of course it is ideal for gamers on a budget - you can get a new Stryke Force for around forty bob. Most of my models are Mantic and Reaper plastics, with a few Onmioji resins and plenty of conversions. It also plays with 15s, which is even cheaper to get into (I'm gonna get some Laserburn 15s for it soon).
Loads more details of game mechanics and such below!:
https://www.wargamevault.com/product/536745/Shadow-Ops--Battle-for-Sephai

