270px-Fusion fall logo

Cartoon Network Universe: FusionFall is a currently in production. It is being developed by and Grigon Entertainment. Cartoon Network has used the as its client technology basis. Though the full game requires a subscription, free accounts can be registered which allow access to a portion of the content. It was scheduled to be released in Summer 2008, but the release date was moved up to January 14, 2009.

Planet Fusion, ruled by the evil Fuse, has traveled throughout the galaxy for millennia, devastating countless planets and civilizations. Earth is its next stop. The player joins forces with the characters from various Cartoon Network series to repel this threat.

The game begins with the player character participating in 's time traveling experiment. As Dexter starts up the machine, Dee Dee, Dexter's sister, sneaks in and messes with the controls. This causes a timejump error, sending the player much further into the future than Dexter intended, where they arrive in the midst of a war between the Fusions and Cartoon Network's characters. This section of the game serves as a tutorial, introducing the player to the controls and items in the game. After completing the tutorial, players are tasked with repairing Dexter's time machine to return to the present. Upon gaining four Nanos and completing a number of key missions, the time machine is considered fixed and the player can return to the present for the main portion of the game. Characters from various original Cartoon Network shows appear in the game, redesigned in an style by Mario F. Piedra. In addition, small, miniaturized versions of Cartoon Network characters called Nanos are collected along the way and travel with players, providing powers and abilities to assist during missions. A prequel, co-written by Matthew Schwartz and Megas XLR co-creator , entitled FusionFall: Worlds Collide!!, was passed out during '07. Due to the overwhelming success of the manga, is in talks to write a script for a FusionFall feature based on the manga to accompany the game's launch.

In FusionFall, the player takes control of a customized avatar to traverse the world. Their character is viewed from a , and the range of movement consists of walking in any direction and a short-distance jump. The game has large playable environments, with travel facilitated by various warp points. Gameplay primarily focuses on defeating fusion monsters for various reasons. The player is provided with numerous weapons to accomplish this, including projectile weapons (pistols, rifles, shotguns, and rockets), melee weapons, and grenades. Unlike ordinary , the player does not gain experience in the conventional sense. Instead, they gather a loose analog known as fusion matter (which has multiple purposes) through defeating enemies and completing missions, and upon collecting enough can perform a mission to raise their level. The player is guided in their quest by a specific character, beginning with Dexter's computer, Computress. After leaving the first level, they can choose between a wider range of guides, and can switch between these guides at their discretion for a small fee.

The main focus of the game is the completion of missions. Missions are given by various characters (for example, of Codename: Kids Next Door) around the game world, who usually cluster around travel hubs. Missions come in three types: Nano missions, Guide missions, and World missions. Nano missions are granted automatically once the player gathers enough fusion matter. A meter encircling the minimap shows the player's progress in this regard. Guide missions are special tasks done on the behalf of the guide character, typically offering the best equipment available as a reward. World missions are generic tasks which offer lesser rewards, but are far more numerous to compensate. Unlike the first two types of missions, which can only be done one at a time, the player can run four different World missions concurrently.

The key to progressing in the game is the collection of Nanos, thirty-six miniaturized versions of Cartoon Network characters which serve as allies in combat. The player's level is tied to the number of Nanos they have collected (eg. a player at level 6 will have six Nanos). Nanos are obtained during Nano missions, in which the player must defeat an evil Fusion doppelganger of a Cartoon Network character. A Nano of that character is granted to the player upon the doppelganger's defeat. Once obtained, players can choose between one of three abilities for the Nano. The chosen ability can be changed later for a fee. Nanos grant a wide range of abilities depending on the specific Nano, ranging from increasing the player's performance (run speed, jump height, etc.) to special attacks (stunning moves, area-effect damage, etc.), as well as a number of player-cooperative abilities in the same vein. Players are limited to carrying three Nanos at a time, which can be switched out at certain stations. Once activated, Nanos will aid the player until they are put away or tire out, at which point they will vanish until rested once more.

In terms of difficultly, a solo player can progress in the game without much trouble. Enemies in any given mission will usually be within the player's ability to defeat, though it is possible to be overwhelmed by sheer force of numbers. So long as the player isn't under attack, their health will regenerate fairly quickly, eliminating the need to replenish health between missions. If the player passes out, they are revived at a nearby respawn point, called a "Resurrect 'Em", the only penalty being a moderate drain of the energy of the player's Nanos, which also regenerate (albeit at a somewhat slower rate).

The game world varies between open and closed arenas. For the most part, missions take place on the surface with the other players. Enemies on the surface respawn quickly, thus making sure that even a large number of players performing the same mission can complete it in a timely fashion without having to wait for their targets to appear. There are also sealed-off areas that mix elements of platforming with an abundance of dangerous enemies. These areas contain one or more Fusion lairs, the end point of Nano missions, and certain regular missions. When entering a Fusion lair, players are spawned into an isolated dungeon, preventing others from interfering. While solo play is made possible, players can group together to tackle tougher enemies, sharing the rewards from victory.

In the game usual villain leaders were called Fusion-Clones a clone made of Fusion-Matter and a persons DNA taken from a personal item.