Metroid Fusion, also known as Metroid 4 was created by Nintendo R&D1 and published for the Gameboy Advance and is chronologically the last game in the Metroid series.
Metroid Fusion is different from other Metroid games as it is very linear and introduces a non-playable cybernetic entity who gives specific objectives to Samus, as well as certain power ups when they are pertinent to get them, thus making sequence breaking and exploration nearly impossible.
The game begins with Samus Aran exploring SR388 with some Federation researchers and getting attacked and infected with the X- Parasite. In order to save her life the organic components of her Power Suit that had become so integrated with her body had to be surgically removed, dramatically altering its appearance and spliced her DNA with that of the Metroid, the X-parasites natural predator making Samus a hybrid creation. Now with the mimetic X-parasite having made a copy of her through the removed suit parts, Samus knows what she has to do.
As mentioned prior, Metroid Fusion is much more linear than other games in the series. The station’s computer gives Samus objectives throughout the game, and its ability to lock and unlock doors depending on the objective renders exploration outside of the objective’s area nearly impossible. This controls the sequence of acquiring powerups, defeating enemies, and reaching certain areas. Therefore, the only exploration that can be done at a given time is limited almost exclusively to secret rooms along the way to each objective.
Another radical deviation from the classic formula is that the environments in Fusion also change throughout the game such as corridors becoming permanently blocked by explosions, parts of the research station are completely destroyed, and new creatures appear in previously explored areas. Some gameplay elements differ significantly as well, including disabling single-wall jumps, mid-air bomb jumping and other methods commonly used to perform sequence breaking.
In order to add some balance however, some new gameplay mechanics were added such as the able to grab on to ledges, which would later become the Power Grip upgrade in Metroid Zero Mission, and in place of the Grapple Beam, Samus can now climb special ladders and “monkey bars” to span large heights and gaps.
Metroid Fusion was very well received by critics, the main criticism came from the game being so linear.
Metroid Fusion is the only Metroid game to be able to be completed with 0% completion
