I played Kirby's Dreamland for the Game Boy when it came out. Loved it at the time. Kirby's Pinball is fantastic too. But my recent forays into Kirby have been unsuccessful. Nowadays I find the games far too slow and straightforward. The Wario Land games are also great. Don't remember how many were released for the Game Boy, but I played at least two of them when I was a kid/teenager. Now, though, I imagine I'd feel the same way as I do about Kirby.
Shovel Knight is a very challenging platformer, and a frustrating one, but the difficulty of the game comes from great level design (and sometimes trolly enemies), so I don't hold its difficulty against it. I feel like I'm in full control of my character in Shovel Knight. My fate is in my own hands. Whereas in Ratchet and Clank things like the camera prevented me from being in full control and many deaths felt like cheap bullshit. Shovel Knight is so much smoother in comparison. Hell, you have a ton of relics (gadgets) in that game too, but shuffling through them is a breeze and can be done at the same time as moving around without compromising your movement and combat too much.
There are 2D Crash games?!