I played all three at the time, I only beat the first one when I was a kid.
2, definitely turned out to be pretty cheap, overall. When it's good, it's GOOD, but when it's cheap, it's downright infuriating.
The main problem I had with the first game is, the run button is the same button as the attack button (roll/spin) and it's the same button that can launch you out of a barrel. So, a lot of times it was like making me roll or spin, when I wasn't moving my thumb causing me to die, or it'd immediately launch me out a barrel. The context sensitivity of that button in the first game is atrocious.
The second game does something that's extremely cheap: it doesn't save your currency or lives. That's just bullshit. And, the way the charge works for the animals, specifically the snake, is nonsense. There's a lot of little things in the game that are really unpolished and make the game particularly unfair. Then the game has a design that will inherently punish you for its own shortcomings.
I don't have 3, and I don't own 2 either, I'm borrowing it. I was going to buy them ... but the prices fluctuate in the extremes. ($15 one week, $40 the next)
Anyway, DKC2 is a good game, but a lot of it pissed me off and I think the Retro made Country games are significantly better. And they have significant challenge. The primary difficulty in the SNES games (so far) has been from issues with the game.
Nope.