Both characters can grab onto ledges to pull themselves up to areas or use it to save themselves from a fall. While either character can complete the game without the other, Fargus must use Sid to reach certain areas and his combustible power-up in two of the levels. Beyond that, I concentrated on Nikki. First, because she is Nikki, and second, because of her double jump. Nineteen levels stand between you and this goal.
Some levels contain bosses.
The most interesting is Mr. Schnebelen. You ride in a small turret like cockpit on the back of a vehicle as he chases you through a tunnel shooting steel balls. You must deflect the balls either at him or explosive canisters along the walls to cause damage. The bosses also require far more than the traditional 3-hits. The tank level requires you to control a turret up and down and a full 360 degrees as you contend with enemies both on the normal plane and in the foreground and background.