I went and played
Mars Matrix.
Blimey, this game doesn't fuck around

such high bullet counts! It seemed totally intractable at first; either designed for god players, or some sort of cruel joke about resource management.
Then you figure out that tapping the GHB instead of full-dumping it is a good move, which lowers the challenge to a more manageable "testicular crowbar massage" level.
Still, christ, a bit beyond me I think. Dig the idea of giving the player a fresh source of iframes every few seconds, but the cost is steep indeed!
To unwind, I tried out
Border Down. And lemme tellya, that was a mistake.
The game has moxie, I have to give it that. Along with the fascinating property of being the 'fixed point' of a certain generation of 2.5D shooters; there's so much design DNA in there that would end up in R-Type Final, Dariusburst, etc. that it feels like a paradoxical time capsule of sorts.
But alas, the titular system is unforgivable. Old-school checkpoint mechanics can be trying, but getting shunted off to a totally different stage every time you die is downright Machiavellian. Smash cut to static; memo opportunities are $1,
pay up sucka!
Probably worth coming back to with savestates, or perhaps via the Dreamcast release if the home consolification has some nice features; It's got cool bones, but the choice of arcade model kills it dead for my impatient ass.
So, nerves frayed, I played a credit of R-Type and made it to the Stage 4 boss. Pretty average run, with a recovery on the battleship stage, but it feels good to be able to do off-the-cuff with no expectation of success.