The game is made up of eight levels and in each level you play as a different Toa (the heroes of the Bionicle universe). In order the levels are:
Players have a ‘stamina gauge’ in the game which acts as a health meter. The stamina gauge has four sections and each time the player is damaged one of these sections disappears. Should the player’s stamina gauge completely drain they will fail and be reset to the last checkpoint in the level. Enemies will sometimes drop ‘Amana Volo Spheres’ which let the player recover two sections of their stamina gauge.
Apart from stamina, players also have to manage their elemental energy gauge. To attack enemies players must target them and then launch a ball of elemental energy at them, depleting their own elemental energy. Hitting the attack button three times with the correct timing will also launch multiple bolts of energy at enemies. Players can recover elemental energy by standing still and elementally charging at any time or by blocking enemy attacks. There are also a small number of Kanohi (powerful masks) of elemental energy in the game which when collected completely recover a player’s stamina and elemental energy.
In addition to defeating enemies, elemental attacks can also be used to activate switches or open canisters. Some levels also cater to Toa’s own personal special abilities; only in the Gali Nuva level is swimming gameplay encountered, only in Onua Nuva’s level can you push heavy objects, only in Kopaka’s level can you see in first-person and only in Takanuva’s level do you have unlimited energy and a ‘double blast’ attack. Gali Nuva and Onua Nuva have the special ability of being able to execute ‘Nuva Blasts’ after charging their elemental energy, doing exceptional damage to enemies or destroying ‘dark cages’. Lewa Nuva and Takanuva also have the special ability of being able to glide through the air.
While the majority of the game consists of standard action-adventure gameplay, the Kopaka, Tahu Nuva and most of the Pohatu Nuva levels are all essentially vehicular missions in which the player is constantly moving forward through a linear level. Kopaka’s level involves snowboarding down a mountain, avoiding obstacles in some sections and defeating enemies in others. Pohatu Nuva’s vehicle section involves moving a mine cart along a set track with the ability to speed up, slow down, jump over damaging obstacles and lean left or right to grab elemental orbs necessary to keep the cart moving. Tahu Nuva’s level consists of surfing across lava, racing a Rahkshi to the end of the level, dodging obstacles which may slow him down and attacking the Rahkshi to slow its speed. Some levels also end in boss battles and Takanuva’s level is particularly notable as it is entirely a boss battle.
Throughout the game there are also a number of ‘lightstones’ for the player to collect. Collecting lightstones unlocks additional content within the game. Additional content includes Bionicle concept art, a trailer for the movie Bionicle: Mask of Light and other small movies. Outside of the main game players can also replay cutscenes and browse information on the Bionicle universe.
The game begins with the Tohunga (elders) and Matoran (villagers) holding a play to celebrate the Toa’s perceived victory over the evil being Makuta, when the area is swarmed by beguiled Rahi (creatures of the island) and Bohrok (machines attempting to sweep the island of all life). The Toa decide to return to their respective Wahi (regions of the island) to deal with the Bohrok threat.
After rescuing a number of Matoran and defeating many Rahi and a group of Bohrok, Tahu finds a Krana (the masks that power the Bohrok) which attempts to take over his mind but he resists and shortly after this the Matoran Takua appears and tells Tahu he has found a new Kanohi. Tahu ignores him and tells him to return to Ta-Koro (the fire village). Tahu informs Kopaka that to defeat the Bohrok they must collect the Krana and so sometime after Kopaka defeats a duo of Bohrok the Toa assemble with a Krana each, transforming themselves into the powerful Toa Nuva.
After speaking to Nokama (Tohunga of water), Gali sets out to rescue the Matoran of Ga-Wahi (the water region) and defeats a Bohrok Kal (one of the elite Bohrok). She then meets Takua who warns her of the Rahkshi (the evil creatures created by Makuta) heading to Onu-Wahi (the underground region). Gali heads to Onu-Wahi to warn Onua of the oncoming threat but finds Pohatu along the way and tells him of the Rahkshi. Pohatu says that he will warn Onua of the Rahkshi and Gali should warn Lewa. At this point they notice a Matoran waving for help but on approaching him the ground collapses under Pohatu and he and the Matoran are forced to take a mine cart to Onu-Wahi.
Pohatu manages to warn Onua of the Rahkshi but they are confronted by Lerahk (Rahkshi of poison). Onua tells Pohatu to run and warn Tahu of the Rahkshi and Onua attempts to attack Lerahk who gets away. Onua eventually works his way through the tunnels of Onu-Wahi to defeat Lerahk. After being warned of the Rahkshi by Gali, Lewa rescues a number of Matoran and defeats Panrahk (Rahkshi of shattering).
Tahu is speaking to Takua about the Mask of Light when Pohatu arrives to warn him of the Rahkshi. Takua reveals that the mask was stolen by Kurahk (Rahkshi of anger). Kurahk heads for Ta-Koro but Tahu manages to beat him there. Turahk loses the Mask of Light and it is placed upon Takua’s face transforming him into Takanuva (Toa of light). Takanuva descends into the lair of Makuta and defeats him for good. Takanuva then places his mask upon Makuta, bonding with him to become Takutanuva and awakens the Great Spirit Mata Nui.