Battletoads

Battletoads is synonymous with extreme difficulty. Rare created a beat 'em up with exaggerated animations (giant punches, hammer transformations) and enormous variety: every level changed genre. But the Turbo Tunnel — level 3, the bike chase with obstacles coming ever faster — is one of gaming history's most famous and frustrating moments. In co-op it was nearly impossible. The game was genius and sadistic in equal parts.