The Lost Vikings is a side-scrolling platform adventure in which the player alternates control of the three Viking characters, guiding each of them one at a time (though control may be swapped from character to character at any point) from a designated start point in each level to the exit. The game offers a two-player cooperative mode in which each player simultaneously controls one Viking and is allowed to change control to the third, unused Viking at any point. Every level is designed such that each Viking must contribute his unique skills to help the other two through to the end. Similarly, to finish the level, all three characters must reach the exit point. The Vikings each have three health points which they can lose by getting hurt by enemies or by falling from great heights. Should any Viking run out of health points, he dies; gameplay will then continue with any remaining Vikings, but the level becomes unwinnable, and the player will eventually have to restart the level and try again. However, the game offers unlimited continues.