Among the folks I follow on YouTube, I tune into The 8-Bit Guy whenever I feel like seriously learning about retro computer history. On top of his hardware breakdowns and restoration projects, he semi-recently made a strategy game for the Commodore 64 called Planet X2. For some time he's been working on a PC-based sequel designed to support even the most ancient of IBM-compatible machines, and recently launched a Kickstarter to further fund development, which hit its target within mere hours.
Before anyone gets smart in the comments, yes, the screenshot above is from the planned VGA mode of the game. In fact, it's technically not even a gameplay screenshot, just a mock-up, as right now the game only goes up to EGA graphics. Planet X3 is designed to scale down to run on nearly any early PC, and be fully playable in four-colour CGA, as you can see in the Kickstarter pitch/work-in-progress gameplay video below.
Planet X3 is a a base-building RTS game, designed around a keyboard-only UI and featuring direct unit control. I especially like the Starcraft-styled missile silos that you can flatten enemy bases with, once you've scouted their territory out well enough to know the exact X and Y coordinates on the map to shoot at. It's perhaps a bit limiting by modern standards, but this is a game designed to fit into a tiny RAM-space and run on 286-era hardware, playable direct-from-floppy.
This is obviously a project for true retro-heads. The kind of people who collect and restore ancient computers themselves, and still have a chunky old CRT or two in stock, but want something a little fresher to play on their ancient hardware. There's no shortage of projects like this lately, with dedicated hobbyists still churning out Sinclair Spectrum and C64 games on the regular, while others create new 16-bit console titles on authentic-looking reproduction cartridges. Limited run collectors items, essentially, but they're keeping the past alive.
Those wanting to get a taste of what to expect can pick up the original Planet X2 (pictured above) off The 8-Bit Guy's store here, although it does cost $20, it does at least come on an authentic floppy disk and come with a full-colour manual. Unfortunately the full boxed version is no longer available. Those backing Planet X3 on Kickstarter get a similar deal - $20 for just the disk and manual - but with $10 download-only options and a $35 tier to get you an authentic DOS-styled big-box edition of the game.