just my general take on all of the generations in terms of difficulty
RBY - Balanced
GSC - Hard
RSE - Balanced
FRLG - Balanced ~ Hard
DP - Balanced
Pt - Balanced ~ Hard
HGSS - Balanced ~ Hard
BW - Hard
B2W2 - Balanced ~ Hard
XY - Easy
ORAS - Very Easy
SM - Easy ~ Balanced
USUM - Very Hard