An orange needs to get through all the levels, collect some citrons and avoid any death. And there is the problem, the dangerous places often appear.
You cannot directly control the hero fruit but you have to use some contact points, which can be sometimes moved and cutting ropes to collect what you have to and get into the exit and so into the next level. The number of levels is ideal and the difficult itself can be really hard or easy trip. But there is an emptiness feeling in the levels.