|Platform||OS X, Linux (source only)|
What would X-COM look if you left out non-battle phases? Have a look at Traction Edge. Version 0.1 is not much beyond technical demo but already gives you several officers to choose for each of three patrol missions. Your objective is to eliminate all opposition. Choose people with at least 10 points of strength. This allows to carry muskets which are much better than pistols.
You can just blaze through levels. Resistance is going to be small because enemy decision making capability is very limited. They act only if your agents remain in their view. Otherwise you are free to jump from behind an obstacle fire two snap shots point blank and hide again. After you kill last one mission is completed. If you explored fully last level but cannot see anything to shoot at destroy some walls. Surely some slither was placed inside stone.
Traction Edge was first released for ARRP 2010. Next version was announced to be revealed on ARRP 2011. To check out the game you need either to have OS X or compile from sources.