As good as the Metroid Prime series is, it's nice to get back to some 2D Metroid action, warts and all.
For those who sympathize, the GBA has been a welcome blessing as it has--through many quality ports, sequels and original titles--kept the 2D dream alive.
Metroid Fusion tries to continue this trend to varying degrees of success.
On one hand it's great to have the similar gameplay from the original Metroid and the brilliant Super Metroid return. Also the setup and storylines are well executed and the action is intense and enjoyable for the most part.
At the same time the story itself makes sweeping changes to the Metroid legacy, many of which are likely to be ignored in future Metroid titles but not a few of which were clearly done for gameplay variety reasons that ultimately weren't really necessary.
And the gameplay is exciting but the level design suffers in more than a few areas by requiring an excessive amount of backtracking to get to inaccessible areas (sometimes that were only inaccessible moments before an item was collected) and frequently results in getting lost or having to trek back to the computer room in order to get more clear directions from the AI Commanding Officer.
As a matter of fact the whole game begins to dive into frustrating territory rather quickly as some of the boss battles are very challenging and many of the mazes and puzzles get increasingly obtuse. Being stuck fighting the same boss dozens of times to get the timing down right may sound like fun to some people, but most will probably rather not bother.
Which is a shame because previous Metroid titles have all been at times difficult but rarely annoying as Fusion can get on occasion.
If you can overlook some of the frustration (which is one of the few things the game designers did to prolong the experience since the main mission is surprisingly short) you'll see a game that shares a lot in common with the classic platformers of the past. And that's a very good thing.
There are some interesting but generally pointless things you can do by linking Fusion to a GameCube via the link cable and Metroid Prime like give Samus the Fusion suit in Prime, but that feature adds little value.
In the end the game is enjoyable but not without faults and short enough that if not for some aggravating spots of high challenge the game may be beatable in a single evening. It's fun while it lasts but you can't help feeling that you hope this was a shortstop and not supposed to be the swansong for Metroid in 2D.