whut?
Donkey Kong (GB, 1994)
Super Mario Land 1 + 2
Wario Land 1-3
Metroid II
LoZ: Link's Awakening DX
LoZ: Oracle of Ages
LoZ: Oracle of Seasons
Trip World
Mole Mania
Mega Man 5 (GB)
Kirby's Dreamland 1+2
Mysterious Murasame Castle (NES)
if you want to play Kirby's Adventure, get the 3D Classics version.
Some good suggestions but some of the games you listed don't feel worthy of being called must haves.
I personally didn't like DK that much but it does have a lot of content and variety. Don't know why it didn't click with me because I really liked the GBA sequel.
SML 1 is really short and basic. Sure the music is catchy and the different locales are really fresh but it's over in a flash. SML 2 has a world map, secrets and retains the weirdness but it's really easy (last level not included).
WL 2 is way better than either WL1 and 3 and I wouldn't say those 2 are a must have, unless you really like the series.
Metroid II is repetitive, really zoomed in and linear.
The Zelda games are great
Trip World- haven't played it yet.
Mole Mania is a nice puzzle game with some funny cutscenes.
MM 5 (GB) -haven't played yet.
Dreamland Land 1 is so easy, basic and short that it hurts. Hard mode doesn't add much either; I was done with the game in less than 2 hours. DL2 is a much, much better game
MM Castle -haven't played this one yet
I would add for Game Boy:
Bionic Commando is really satisfying once you master the swinging mechanic.
Donkey Kong Land 2&3 are nice platformers with lots of levels and secrets. Stay away from the first one.
Gargoyle's Quest It's short (~5 hours) but it's a nice mix of platforming, action and has some light RPG elements. The broken English translation (not a problem) is also funny.
On Game Gear I liked Vampire the Masqurade (Castlavania for babies but only lasts a bit over 2 hours) and Shinobi (hard and the last level is a gigantic maze).
If we're including NES
-Ninja Gaiden 1 >3 >2 An unforgiving action game series with great music and tight controls.
Castlevania 1 & 3: 3 is my favorite but it's also way harder so it might be better to start with 1. An ''action'' platformer that demands precision and patience, lots of patience.
MM 1-4; Liked all of them so far with 4 being my favorite. 1 is unpolished, 2 has a really, really stupid boss fight and 3 has way too much slow down.