Real talk, I would pay for someone to make a proper Metal Slug openBOR game, where you play as basically every Metal Slug character, and can traverse every level of every Metal Slug, just killing and probably getting killed. Cause honestly, nothing would be better than seeing an ACTUAL Metal Slug beat 'em up, and I'm not talking using the MUGEN style of Metal Slug characters, no no no, I'm talking using the Metal Slug sprites from the actual Metal Slug franchise. Turning that platformer/shooter into a beat 'em up would be pretty sweet. Unfortunately, I don't know jack squat about how to make a game, and based on the tutorial videos I've seen, it looks far too complicated to me. Like, I was expecting it to be much easier, but apparently it requires a hefty amount of "coding" and whatnot, which I'm completely crap tier at.
But in all honesty, if someone were to make such a game, I would gladly give them money for their work (just so as long as they actually make the kind of game I'm expecting to have made).