The Cell Games is a melee competition hosted in at the Cell Games Arena. After Cell achieved his "Perfect" form, he became bored and challenged the people of Earth to a tournament to determine the fate of the world, everyone vs. Cell. This tournament was held on May 26, Age 767. Midway through, Cell became bored with the rules: first he destroyed the arena to eliminate ring outs, then he began attacking the spectators to force Son Gohan to break. The tournament ended in a free-for all melee leading to the deaths of Artificial Human No. 16, Son Goku, and Future Trunks and finally the defeat and death of Cell himself via a one-handed kamehameha fired by Son Gohan.
Piroshki advances on Cell but is unable to get close, pushed back solely by the force of Cell's ki. Eventually he is pushed out of the rink without Cell even moving.
Son Goku faces off against Cell. During this battle, Cell adjusts the rules and removes the Cell Games arena, removing the possibly of defeat by ring-out.
Son Gohan steps into the melee and while he seems more powerful than Cell, he refuses to fight. Cell becomes enraged and the remaining trappings of a "tournament" are quickly abandoned as he kills Artificial Human No. 16 and creates Cell Jrs to right the spectating warriors. Gohan cracks, finally becoming Super Saiyan 2. Cell is badly beaten, eventually regurgitating an unconscious No. 18 and reverting to his Semi-Perfect form. Realizing that is is defeated, Cell triggers his self-destruct, but Son Goku teleport the exploding Cell to Kaiō's Planet. Son Goku, Kaiō, Bubbles, and (in the anime) Gregory are all killed. Cell survives and somehow regenerates as "Perfect" once again. He kills Future Trunks which causes Vegeta to attack him in a rage. In the ensuing fight, Gohan is badly hurt protecting Vegeta. Cell is finally defeated by a one-handed kamehameha by Gohan, with an assist from Vegeta distracting Cell just long enough to be overwhelmed by Gohan's ki and destroyed. The Cell Games are over!