Depends on your skill level, understanding of the game's mechanics, luck, and ability to follow instructions. Every game holds its differing degrees of difficulties, but on average, PMD: 2 is challenging enough that it's enjoying but not so hard that you'll break your DS over.
tl;dr: your millage may very.
not really that hard if you got a good team. (riolu and meowth and pikachu and munclax are a few good combinations.)
I think you should buy Pokemon Ranger because mystery dungeon is a little bit annoying and stupid Pokemon Ranger is amazing. I had so much fun playing it. I'm still trying to beat the part were you have to beat Raicu, Suicune, and Entei. It is SOOOO hard. I can beat Raicu and Suicune but never Entei!!!! :(. Anyways, I have never played mystery dungeon but my sister said she didn't like it sooooooo. Go with Ranger :)
very hard
It depends who your pokemon are. I found him very hard.
Hell yeah..
gotta beat darkrie hes hard(darkrie can join your team after you bet him you just gotta find him somewhere)
Rob from a shop and try to beat one there really hard to get. Note there about lvl 90 You can beat them but they are SUPER HARD! But i beat one before. I had a Pikachu, Piplup, and Larvitar. Once you beat them they have backup, they are harder. It cost me reviver seeds, and Oran berries.
It is raquaza and it is really hard to make it join
When you use cheats or glitches. I do not approve of them, personally... But it can be really useful when beating a hard dungeon.
You could go and try to recruit most of the legendaries with a secret slab or mystery part but some are hard to recruit so use a golden mask that will improve your chances you can get these items by using wonder mailhope this helps
Luck He is really hard to get take a friend bow for better results.
It is VERY hard. I tried it and I couldn't do it.