Spartan Strike is the follow-up to twin-stick shooter spin-off Halo: Spartan Assault, and is once again developed by Vanguard Games and produced by Microsoft's Halo custodian 343 Industries.
Spartan Strike is set during the events of Halo 2 on New Mombasa in 2552. There are 30 missions in which you lead UNSC troops through cities and jungles. There's gameplay in the video below.
Microsoft is selling a Halo: Spartan Bundle on Steam for Ł6.99. This includes both Spartan Assault and Spartan Strike. Spartan Strike on its own costs Ł4.79 on Steam.
The Steam version supports keyboard and mouse and USB Xbox controller. The mobile versions use virtual joysticks for touch.