I figure since this game will take place in space at some point we will be mining asteroids. You know... scan the asteroid for what minerals it contains, point a laser at it to break up the rock, then use a tractor beam (modified with ore sensors) to pull in the ore you're looking for 'til your cargo unit is full. And since you have a gun, you have to protect your mining gear while it does its work.
Only challenge is to make it fun unlike other games where you just sit there and monitor your mining gear while sending drones out to defend your setup...
If we'll be planet and asteroid-hopping mercs, why not have factions which will essentially be the pirate-equivalent of that. Something to defend your mining-op from. Should the player character be directly involved, boots on the ground, or merely mine through a mini-game, similar to Mass Effect 2. Liked the process in Mass Effect 1 better. To actually land on a planet or an object in space. Look up. Around. See the moon(s) of the planet. Or the planet from its moon(s). Or from an asteroid belt. THAT is what gave a true feeling of awe, in the first Mass Effect game, apart from the scene where I had to proceed up the side of the Citadel in low gravity, seeing Sovereign clawing away at it. No other game has ever had such a profound effect on me as the first Mass Effect. I definitely loved to see similar elements, if we're going to have multiple planets. Perhaps make it a bit like No Man's Sky, as well. The best from all games, rolled into one. THAT, I guarantee, would be a game to remember. And one I'd pay for.
I also cannot decide if the harvesting of ore should look like as it does in FireFall, where you can see crystals floating around. Or...like in these new planet exploring games that seem to be coming out in droves, where you shoot a beam at the object to strip its part. If I'm being honest, they could easily get away with it, saying it's all done through some fancy omni-tool and it makes the player more involved, so mining/harvesting the ore could and should involve caution, even when not in immediate danger, but especially with hostiles around. Objects scattered on the ground (ore, loot...etc.) should also remain for longer, so people could collect them after a battle is over, but also during that, if they have time to harvest in the middle of a fight, so they wouldn't disappear.
Also, would it be a bad or a good idea, considering risk and reward and immersion, if said objects could be destroyed if damaged enough by enemies?