Persona took 4 games to get it right.
Not really. It was just a few issues.
Persona 1 was just SMT-lite and not in a good way and was dull but the characters were fantastic.
Persona 2 Innocent Sin was super easy and had bad gameplay at most cases and Enternal Punishment was hard as hell but both has the best story in the series.
Persona 3 is really hit and miss in the gameplay department like most games but everything else was pretty decent to great.
Persona 4 is the example of everything aside from design and music was mediocre as hell but the gameplay was perfection.
DKC 2 was perfection ALL AROUND.
Even then most sequels can end up being ****.
Look at DMC 2, Sonic Advance 2, FE2, Zelda 2 and the second PS1 era FF game (FF8)