Super Mario Odyssey and Bowser's Fury could be good choices, since both contain secondary characters for player 2 that can move, hurt enemies and interact with the environment, but can't actually take damage from anything and are in some way tied to player 1's progress.<p>The only issue with the former is that because player 2 controls Cappy, you won't always have him where you need him to bounce off for a difficult jump.<p>Yoshi's Woolly World and Crafted World could work. They're both co-op games like the New Super Mario Bros series, but come with a 'mellow mode' where players can fly around freely and platforming is much easier.<p>Super Mario Bros Wonder is a good choice, since there are characters who are completely immune to damage, and (for the Yoshis) have the ability to flutter jump in mid air to make platforming far easier. The special world levels would certainly be a challenge, but hey, having two players actually makes the game easier for you as well, since you can revive so long as one person is alive.<p>If you liked Kirby, then Kirby's Return To Dreamland and Kirby and the Forgotten Land have co-op multiplayer and work about the same. Maybe Star Allies, but the game isn't really as good as the other two.<p>Oh and Luigi's Mansion 3. Gooigi is player 2's character, and has a way easier time during the adventure than Luigi does, respawning whenever he runs out of health, being immune to spikes, etc.<p>Hope that helps!