Contra: Operation Galuga (Demo) : Multiplayer Local Shared Screen Co-op Campaign ~ Full Gameplay 

𝐒𝐡𝐚𝐫𝐞 𝐰𝐢𝐭𝐡 𝐮𝐬 𝐲𝐨𝐮𝐫 𝐭𝐡𝐨𝐮𝐠𝐡𝐭𝐬 𝐚𝐛𝐨𝐮𝐭 𝐭𝐡𝐢𝐬 𝐠𝐚𝐦𝐞 𝐢𝐧 𝐜𝐨𝐦𝐦𝐞𝐧𝐭𝐬 𝐛𝐞𝐥𝐨𝐰. 😁 𝐌𝐮𝐥𝐭𝐢𝐩𝐥𝐚𝐲𝐞𝐫 𝐌𝐨𝐝𝐞 𝐈𝐧𝐟𝐨 : playco-opgame.com/contra-operation-galuga/ 𝐇𝐨𝐰 𝐭𝐨 𝐩𝐥𝐚𝐲 𝐌𝐮𝐥𝐭𝐢𝐩𝐥𝐚𝐲𝐞𝐫 : playco-opgame.com/how-to-multiplayer/contra-operation-galuga/

Bill Rizer's voice actor is Steve Blum, who also voiced Master Contra(The A.I. of Bill Rizer) from Neo Contra.

Arcade mode can play up to 4 players but there is no story in this mode. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UXC6pq-hyFQ.html

So the demo only can co-op 2 players not 4.

how do u select a second player in pc mode?

No online co-op?