You're a man armed only with his grapple. Being chased by lava, water, and other things that can kill you, you need to go up.. and keep going up until you are far away from any danger. Grapple Hero is a different take on the platform jumper games, where your only means of movement is attaching your grapple to the next platform above you.
Current menu setup, I plan on having three modes of play. Levels, which is a more traditional approach, there will be 4 worlds, each with 4 levels. Endless, you start in the castle/cave area and progress to the woodland area, then snow, and eventually space if you can make it that far. The last mode will be a race mode where you go against an AI opponent, lava or water, and possible other players ghosts.