Round 2! Fight!
What No More Heroes 2 Does Right:
Combat - Several changes have been made to the simple formula of the original every single one of them being for the good.
Minigames! - The side jobs in No More Heroes 2 are amazing in their awesome pixelated glory.
Satire/Parody - There are a lot of things straight ripped out of other games like Resident Evil 4 as an example, and it keeps the gamer guessing what are they going to poke fun at next.
What No More Heroes 2 Does Wrong:
Story - It is not as ridiculous or hilarious as the original. Revenge plots are boring to me by now (see Assassin's Creed II).
Rate "M" for Mature - Sexuality is constantly shoved into the player's face with no purpose but because they can. The language is also just a little excessive (but I already knew that going in after the orginal).
I should also note that NMH2:DS is much more difficult than its predecessor. For a reference: I played through the first game on all three difficulties and probably died less than ten times all together. I died about ten times on the easiest difficulty this time around in the sequel.
It is a fantastic game that really feels like a love letter to gamers. It holds on to what made the first game great, and added enough to make it so much better than the original.
The voice acting is fantastic, the combat is much improved, there are more, though less memorable, boss battles, and the "peepshow" scenes feel entirely unnecessary and kills the otherwise crazy fast pacing of the game.