The Lost Vikings - Definitive Edition, from the Blizzard Arcade Collection.
Classic game in the puzzle-platformer genre, not the first to do "switch between multiple playable characters with different abilities" (apparently Gobliiins came before), but it makes great use of the mechanics to make a lot of fun puzzles, which build up in challenge nicely toward the end. The vikings' bickering is funny too. The definitive edition is basically the SNES version with the extra levels from the Megadrive/Genesis version added, and the extra cut-scenes. Apparently it supports 3-player co-op play too.
Really good game, I was playing through the SNES version on my 3DS before I abandoned that for the Switch, and had intended to use passwords to play the extra levels on the Megadrive version afterward, so having all the levels built-in is a wish come true. I only used the included save-state feature at the start of a level, because passwords are dumb, didn't "cheat" by saving mid-level, so feel good earning the win. 5 stars would recommend.