According to official introduction,
Contra: Operation Galuga is a thorough reimagining of the classic run 'n' gun NES/arcade game from the 1980s, featuring timeless gameplay, iconic weapons, modern graphics and sound, new stages, new enemies and bosses, new play mechanics, and intense co-op combat for up to two players in Story Mode or four players in Arcade Mode! Take control of elite Contra commandos Bill Rizer and Lance Bean as they battle the Red Falcon terrorist group, which has turned the once-peaceful Galuga Islands into an all-out warzone where the fate of mankind hangs in the balance.