I've been playing this one for quite awhile now, but the newest major update has put things in a great state to start singing its praises. It's
Cortex Command, a unique little hybrid of strategy, shoot-em-up and pixel art charm.
It's still very much in development, with lots of stuff subject to change, but even in this state it's a beautiful thing. Get past the initial learning curve and you'll be rewarded with the kind of charming, singular game I didn't think they made anymore. More than anything, it reminds me of those mad, unique games you'd get cropping up on the Amiga from time to time.
Be warned - it's the kind of game where everything can and does go wrong. Whether it's screwing up a dropship landing and frying your freshly deployed troopers' limbs off with your thrusters before spiralling explosively into your main line, or simply misjudging a jetpack jump and smashing your commander's head off an overhang, things can take all kinds of vicious, and sometimes hilarious, turns for the worse. But instead of being maddening, it all adds to the charm somehow.
There's not much of a campaign there yet, but what precious little there is bodes well, and it's already got a decent skirmish mode. And in another nice touch, up to 4-player splitscreen, which is a very rare thing indeed on the old PC. They're working on the Mount & Blade model, where you can buy the game now for cheap (currently a shade over a tenner), play it as is, and continue getting any updates up to and including the finished game when it arrives.
Anyway, I highly recommend giving it a try. Once it finally clicks, there's a lot of fun to be had. I just hope they can keep the quality up as things progress.