Is this game focused entirely on combat?
Hmm… I suppose not, in the sense that the majority of missions have objectives that aren’t directly about combat (eg search for loot, carry contraband across the table, rescue a prisoner, reach safety, sabotage stuff, repair stuff, operate a computer terminal, etc) but then of course it could easily be argued that these are just devices to make combat flow in different ways than they would in a straight-up deathmatch, as opposed to actually precluding combat. Then again on the other hand, by that token there wouldn’t be many miniatures games in existence that aren’t focused entirely on combat.
Some of the locations and scenario complications can also hamper combat to a limited extent (eg the encounter is aboard a spaceship so all ranged attacks that miss cause collateral damage with dangerous side effects, or two characters on opposing sides have a secret connection so they don’t want to kill each other, or EMP is causing equipment malfunctions, etc).
There is a campaign system, so that can give you something to do in between missions. But there isn’t much to it besides checking for deaths and injuries and spending Experience Points gained in previous games to upgrade characters.