Step 2: View Mode
Views changed during the life of the Genesis, but basically there is 4 kinds:
2.5D Side (Sonic 3-D Blast)
Most games were Side scrollers (Sonic 1, 2, 3, etc.), but there were odd ones, too (NBA Live?). There was also a mix of both in some (Phantasy Star?). Heck, there was some games with all 3 (Thunder Force 2: Odd Levels, Even Levels, Title Screen).
Go To Step 3: Programming