A game where you play as a military researcher of an alien civilization at war with the humanity. Your role is to analyze enemy weapons & equipment (based on reports of your soldiers and whatever they may have scavenged) while trying to come up with new equipment for your own army to eventually end the war, either in your or humans' favor.
You can test both yours and enemy weapons that you have at your disposal (all you would get would be the reports since you are not doing those yourself directly), analyze particular parts of the weapons and see how they work, see how you can incorporate your knowledge into your already-existing designs and how to counter the enemy with them.
For instance, you could have received a report from the higher-ups that they need a new anti-armor weapon to deal with the heavily-armored human tanks. You could try to reverse-engineer nuclear weapons the humans have been using previously against you or maybe develop plasma weapons based on the technology you've recently received...Etc.
And then there's the chance that the command doesn't actually like your creation and they turn the idea down, forcing you to make something else and think differently.
So through your actions you could determine the outcome of the human-alien war without ever directly participating in it...
A relevant pic I made (before thinking of the idea for this game):