Sorry I was bashing Primes so hard and praising MML2's innovations compared to Primes that I forgot to mention wwhat makes MML2 a decent 2d to 3d adaptation.
So here's a rundown.Movement in General
Platforming is a thing in MML2, it's not there for show. You actually have multiple situations where you have to platform while you're under attack by enemies. You can either use your platforming or shooting skills to solve this, just like in the 2d classics. This is aided by the game's DOOM1-esque slow porjectile speeds.
Yes the projectile speeds are relatively slow, meaning it's entirely possible to do a no damage run, granted IMHO much harder due to the z axis aspect. This works in benefit to the game though, since while you can turn Megaman/Volnutt into a tank through upgrades, it's perfectly possible to play through the game with no health upgrades and gracefully dodge all sorts of incoming projectiles. This is a level of liberty also allowed to players in the old Megaman 2d games. Moreover this is a design choice that makes Legends 2 and the old games so fun to play, the enemy projectiles are actually fair and reward your dexterity at bobbing and weaving through them.
Talking about enemies, the enemy bosses in this just like the old games are able to zip, whiz, jump and teleport around the battlefield. While every once in a while you'll be against heavy tanks that will punish you if you're not good at dodging their attacks. Just like in the old games there's also invincibility frames when you receive damage, however there's also a new addition, the rolling dodge actually has invincibility frames as well.
Disappointingly so, but faithfully however the standard enemies in the game don't really have interesting movement mechanics. It's just like the classics, there are enemies that will slow down your movement if you're not careful, enemies that will punish you if you spam the jump button too much, enemies that will punish you by overcrowding if you fail at properly engaging in crowd control, and as previously mentioned, enemies that will punish you during platforming segments just like in the original if you underestimate them.
It's not a perfect adaptation though, the dashing and sliding mechanics introduced in MM7/8 and MMX are not present, however it's understandable why. Such mechanics require really large levels which the consoles and arguably even PCs of the time couldn't afford to render without significant sacrifices to graphics. So instead we have the rolling dodge mechanic that has invincibility frames and a compromise of sorts in the form of the sideweapon roller skates which can be used to explore ruins you've cleared, and the hubworlds as well.