Fan games are unofficial games based on the Super Smash Bros. series, but created by fans with low or non-existent budgets. While they are unofficial, they are sometimes considered an important part of the Smash Bros. community. Multiple fan games have been created, each with their own fanbase. As a difference to retail products, fan games are free, and require a simple internet download. Fan games often add characters many fans want in the official Smash Bros. games, and are made with completely 2D sprites and backgrounds, compared to the 2.5D of the official Smash Bros. games. Many fan games also tend to have considerably simpler mechanics than retail games; Super Smash Flash, for instance, only gives roughly five moves to a character, while MultiHero characters have around seven.
While there are many popular fan games, among the most well known include Super Smash Flash, its sequel Super Smash Flash 2 and Super Smash Bros. Crusade. Numerous other exist, such as Super Smash Bros. NES and MultiHero.