Man... is this... the best one??? I dug this one way more than I thought I would. Great stages, great bosses... in a lot of ways this feels to me like a "fixed" version of Mega Man 2. You've got the slide and charged shot here now, you don't have anything like Metal Blades being the overpowered answer to every situation, you don't have bosses turning to dust the second you enter their room with the right weapon, there's no freakish difficulty outlier like boobeam or yellow devil... You've got a secret side-collectible thing but it's just a useful and fun bonus, not something secretly mandatory like the Magnet Beam...

Yeah I'm gonna say it, this one totally rules. If you're looking for something harder, you'll like 3 more, but if you're a big fan of 2...? I think this is the one to check out. It's hard to quantify why I feel this one is so much less bland than 4, but there it is.

Edit: I've figured out why I like this one so much more than everyone else seems to... I don't use the boss weapons outside of hitting boss weaknesses and I never have. Turns out the main complaint people have with this one is the weapons. Well, if you're usually a buster-only hero like me, you'll be right at home.