2D Sonic games or 3D Sonic games? Why?

[DevilRising]

2D Sonic. Because some games/franchises, just did not/could not make a successful transition into 3D. Some games are better off staying 2D, and are always better in 2D. Such as.....

Sonic
Contra
Metroid (not counting the Prime games, which were good FP games, but Other M was garbage)
Ninja Gaiden (IMO)
Castlevania (IMO)
etc.