hardest game

[Galuf]

Any. Wether spin off or not.

I think due to randomness. That mystery dungeon 1&2 are the hardest.
Tgough no game i played is really that hard

[Skyblade]

Hardest game overall? Really hard to say. Probably one of the Mystery Dungeon games due to how the mechanics work (no control over your team members, and they'll attack a Pokémon that's used Destiny Bond, for example, killing you).

Hardest standard game? I think White 2 in Challenge Mode is supposed to hold that honor.

Hardest final boss? Pokémon XD: Gale of Darkness, if you attempt to capture all the Shadow Pokémon in one match (the way you're supposed to).

[wizzyboo]

Pokemon gates to infinity (SPOILER) after you complete the main story and you have to go through that dungeon as your partner to get your main back ... If snivy was your partner ( its a fire dungeon and you can't bring any others with you) you're gonna have to grind a lot to get through

[Fynn]

From the main games, probably the first generation. The level scaling was just insane. You had to grind like 20 levels between gyms, IIRC.