'Full(ish)-fledged spaceship sims but at a tiny resolution' is a trend I am most in favour of. I first encountered it in the hugely impressive Norman's Sky, which squished the enormous sci-fi game into a 64x64 window, and I encounter the trend again in Black Firmament 2: PAX. It's Wing Commander, or Freespace, basically a space dogfighting game, but in a window the size of a thumbnail.
Obviously, 64x64 is not an ideal resolution to play at, even when the image is blown up to fit on your screen, but I'm impressed by just how readable Black Firmament is despite that. HUD elements can be clearly made out, and enemies distinguished from the black-purple background, if only by the colour of their smeared pixel trails. If you can get used to how it looks, it's an enjoyable, simplistic dogfighting game that captures the essence of the genre with the barest components.
Resolution aside, there aren't too many of these games about now, particularly that you can play in your browser. So take a seat, try not to cut yourself on the pixels, and do try to blast every last one of your enemies to smithereens, in this ridiculously teeny action game. (Thanks, Warp Door.)
For more great free experiences, check out our roundup of the best free PC games.