Game play
Once the player has earned a Nano, it can be summoned to aid them. Nanos will generally float just above the character's right shoulder, though they will occasionally hover around the player in a small circle. Players can carry three Nanos at any given point, which can be swapped for others at a Nano Station. The player's current Nanos can be seen in the bottom-right corner of the screen, arranged by slot order (1, 2, and 3).
Each Nano has three Nano Powers, one of which the player must select upon the Nano's creation; e.g. Numbuh Two helps a player run faster, while Mandark makes a player and their group jump higher. The chosen ability can be changed later at a Nano Station for the price of one appropriate Power Item and a certain amount of Fusion Matter (based on the player's level). There are a total of 36 Nano Powers, and three copies of each power, one for each Nano type. Nanos must be summoned for their powers to be used.
Every Nano has a stamina bar, which determines how long they can remain active. A summoned Nano will slowly lose stamina until it runs out. Stamina can be regained by giving Potions to the Nano or putting it away to rest. If the Nano has a passive power, its stamina will drain at an accelerated rate. Powers that require manual activation will drain a large amount of stamina at once. A Nano with low stamina will become visibly tired. If a Nano runs out of stamina or is put away while tired, its picture will sink, and the player must wait for it to recover a minimum amount of stamina for it to become usable again. You can recover your Nanos' stamina by giving them Nano Potions. Guard, Antidote, and Freedom will drain some stamina when the effect to counter is triggered. Like if a player gets stunned by a monster, the Freedom Nano will lose some stamina to stop it, same with Guard and Antidote. Recall and Revive - Group will drain a severe amount of stamina. Now Finn, Rex, and Alien X Nanos are now avaible. Coming soon are Cheese and Johnny Bravo nanos. Also, in the graduation area there seems to be a "Nano creation chamber" with nano versions of Mordecai,Rigby,Jake,Rath, Way Big and Ultimate Big Chill have been seen with what appears to be unstable nanos inside. Hinting that these characters and more characters will be added in the Future. When you go on to the FusionFall home screen there are shadows of to-be Nanos.