You got it! Your turn!

Edit: my attachment isn't attaching. It's under 2 mb. I'll have to pass

There are many websites that allow you to resize a picture online, without the need to install any software. I just type "reduce image size" on Google.

2MB is a limit for all attachments, for 1 pic it's just 500KB. ;)

Adding to what others have said, if you can't figure out how to resize the screenshot, you can just upload it to imgur or something and post a link.

Looks like they're not going to be posting the next one, so next turn's up for grabs to the first person who wants it!

Sorry, I was away for a bit and assumed someone would have taken my turn by now. I resized it to under 500kb. Thanks triock.

Looks a lot like Sid Meier's Colonization but in a more modern take, but certainly not the Civ IV one. Maybe FreeCol?

Bingo! your turn.

Not an actual gameplay screen (yet), but a crop from the intro sequence. It's from an arcade 3rd-person space shooter.

Okay so that crop was maybe a bit too arbitrary, had to do it because a) I wasn't around yesterday and b) no longer have savegames and have to play myself in order to get some usable screenshots going again.
As a hint, the game in question is less than 15 years old. Full screencap this time :)

I knew that Beholgar, my brother plays it

Strike Suit Zero? I'd consider it more of a space combat sim than an arcade shooter though.

Strike Suit Zero is very much the correct answer, but while you have a bit more to consider than plain shoot-to-kill there's no inertia, you can't apply horizontal or vertical thrust (eXcept for the dashing in "suit mode")... At least some sort of zero-G feel should be there and SSZ doesn't have that, but it's mad fun regardless!

Your turn, good sir!

Aight, next one!

Most classic space combat sims like the Wing Commander and X-Wing / Tie Fighter series are like that.