I think my list from over here is still pretty solid:
Late to the party but I got a Switch for my birthday, woo! I picked out two games so far. Friend said play other games before starting Zelda Breath of the Wild (cuz I'd be ruined for other games?) so I played Hades first. --- I like it a lot! First time to play anything... Rogue Like...
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But, hitting some highlights for what you might enjoy the most....
Pick up and play games:
Super Mario Odyssey-It's a no brainer, but I get the feeling you might be avoiding 3D games on your Switch Lite. Personally, I don't think there's any need to, I think this would look fine portable-only.
Kirby and the Forgotten Land-Probably the most ambitious Kirby game we've gotten in a while. It is 3D though, so if you think you'd prefer 2D on a portable screen, maybe try Kirby Return to Dreamland Deluxe instead. Personally, I think Forgotten Land would be fine portable.
Teenage Mutant Ninja Turtles: Shredders Revenge: Dimension Shellshock-There is a physical version with the DLC on the cartridge. There's also the TMNT Cowabaunga Collection which collects most of the 2D TMNT games for the NES, Gameboy, SNES, and Arcades.
Shovel Knight Treasure Trove-You've probably already played this, but it's still a solid platformer with all the DLC and alternate characters included.
Rayman Legends-Again, you might have already played this. But, it's a really solid platformer if you've never checked it out.
Sonic Mania Plus-One of the best Sonic games in years. There's also the Sonic Origins Collection which gives you the 3 Genesis games and CD, along with a few Game Gear games.
Yoshi's Crafted World-It's easy, but fun.
Shantae and the Seven Sirens-The entire Shantae series is actually worth checking out. But, this is the newest one. I also highly recommend Shantae and the Pirate's Curse, but that might be easier to get digital.
Pikmin 4-Probably the best Pikmin game on the Switch. And ALL of them are on Switch. Again, it's 3D, but I think it'll work handheld-only.
Luigi's Mansion 3-It's getting close to spooky season. I think you'd enjoy this game.
Disney's Illusion Island-A easier game. But, it's fun if you're a big Disney fan for all the easter eggs.
Light RPGs:
Pokemon Legends Arceus-This still gets my vote for the best Pokemon game on the Switch. And it tries something a little different with it's catching mechanics.
Live A Live-This is probably testing the limits of what a "light RPG" is defined as. It is a remake of a SNES game that never originally made it west. And the story is broken up into sections, so it would be fine to play in "chapters".
Cat Quest 1 and 2 Pawsome Pack-There's a collection of the first two Zelda-like games. And there's also a third one, which might be the best one. Take your pick.
Nexomon 1 and 2-If you don't want to try Legends Arceus, this indie game plays a little more like the older GBA or DS entries in the Pokemon series. There's a collection with both games in one.
Digimon Story Cyber Sleuth 1 and 2-They're probably the best Digimon games. Again, if you want something Pokemon-like.
Cadence of Hyrule-This is kind of a different rhythm/action game with the Zelda cast. It's good. Plus, there's a mode that lets you turn the game into something more turn-based if you're not good at rhythm games.
Advance Wars 1 and 2 Re-Boot Camp-If you have any nostalgia for these strategy RPGs, they might be worth revisiting.
Wargroove 1 or 2-If you want Advance Wars but something new, this plays VERY similarly.
Eastward-A charming RPG with a beautiful art style.
Since you said you like fighting games:
Super Smash Bros Ultimate-Yeah, this is a no brainer. I think you'll have a good time with this.
Capcom Fighting Collection-You get ALL the Darkstalkers games, along with a few hidden gems.
Marvel vs Capcom Fighting Collection-The digital version is already out. But, you'll have to wait until November for the physical version.
Digitial only games:
Blossom Tales 1 or 2-If you want some more 2D Zelda, these get pretty close.
Cross Code-Another solid Zelda-like game with a great story.
What The Golf-A crazy, funny golf game that plays more like a puzzle game.
Donut County-A light, funny puzzle game where you control a hole. It's more fun thatn it might sound.
Penny's Big Breakaway-A fun Sonic-like 3D platformer.
Freedom Planet 1 or 2-Solid Sonic-like 2D platformers.
Klonoa Fantasy Reverie Collection-You get the first two Klonoa platformers, which are very charming 2.5D games.
Famicom Detective Club 1 or 2-We're getting a third entry in this series of mystery visual novel games. So, maybe you want to try out the series?
Arzette the Jewel of Faramore-If you've ever heard of the Zelda CD-I games and wanted to try them out, play this instead.
Sam and Max 1-3-All the 3D point and click comedy classics are now on Switch. They're a fun time.
Scott Pilgrim Vs the World The Game-A really solid beat-em-up.
River City Girls 1 or 2-Another solid beat-em-up series.
Bug Fables-If you want a game that plays like classic Paper Mario RPGs, but with a new cast, this is the game for you.
Born of Bread-Another Paper Mario like RPG.
