R-Type isn't that hard once you know "the dance". I wish we had R-Type 3 available.
CV and Metrovania don't have much in common, CV is completely linear and very slow compared to MV. The physics are unwieldy, the movement very rigid. Obviously there's no stats either, only pickups (and the damage boost pickups don't seem to do a whole lot, I don't think many enemies take less hits with them applied). Like all VC games the manual is very incomplete and the least understood item (roman numerals) isn't described. For reference, the numerals allow you to have two or three special weapons on screen at once and are lost when you switch weapons. So far (first castle stage completed) SCV isn't that hard but dropping into holes is instadeath and can be frustrating because you can't influence your movement after you get hit so you can easily get knocked into a hole. Overall the music is crap in SCV, though. Makes you think it's a Megadrive game.