user: Question: Which main developer made their first release in 1991 and created the Mega Drive/Genesis console?
Columns: ['Franchise or Game', 'Console', 'Main Developer', 'Main Genre', 'First Release', 'Latest Release']
Types: ['text', 'text', 'text', 'text', 'real', 'real']
Sample row: ['After Burner', 'Arcade , PlayStation Portable , PlayStation 3', 'Sega-AM2', "Shoot 'em up", 1987.0, 2010.0]
SQL:

assistant: SELECT "Main Developer" FROM "Table" WHERE "First Release" = 1991.0 AND "Console" = 'Mega Drive/Genesis';