What are some sick 16-bit Co-op games?

[masschamber]

Words Of Wisdom said:

masschamber said:
Genesis,, only things I haven't seen mentioned
Contra Hard Corp, play the Japanese release unless you wish to suffer greatly

That makes no sense at all.

Japanese version you get 3 hits perlife and there are extra life codes,

the US release you get 1 hit, 3 lives, 3 continues,

Japanese release is really hard, but the US one is insane