This game is so awesome. I really think it's a fun, entertaining game that is both challenging and has a good story line.
story-9
 So the game starts off after Mega Man X 3, Where you had destroyed sigma for the last time and his virus...or so it was thought. Sigma comes back and infects the new generation Reploids (Robots who can feel and think for themselves) causing them to go maverick and kill humans.
X and Zero go to stop sigma and his new plan for creating a new era of nothing but Reploids.But sigma takes over a satellite base in space and also plans to bash the satellite into Earth and annihilate the humans.
The fate of Earth is in your hands as you defeat the maverick Reploids in hope to build a cannon to stop the base from crashing into Earth.
Can you do it?

This review looks incomplete...all you talked about was the story. Are you planning on talking about anything else about the game? Summon me if you add more to this review.

Nothing wrong with an incomplete review for a first timer.
But
What about the new characters (Other than the "Mavericks")?
What about the Loading times and Cut scenes?
The Button sensitivity and the differences between the S.N.E.S. Controller and the Playstation Controller? (Particularly with the "D-Pad".)
The Musical Upgrades?
The Enhanced feeling of "Speed" when playing. (If I remember there was a snow boarding level section that was brutal but fun.)

There was a kind of rebirth with Megaman in this game and it was a great celebration of "2D" Graphics Not Dying if Memory serves. (Everyone was making everything "3D". Witch was not always needed.)

The Cool Part of MegaMan X4 is the history that it made with an industry that was pushing too hard to go "3D". (Remember "Rival Schools"? No. Why? Looked too much like a "Tekken" Clone? But had Capcoms Stamp and some Sweet Tag Team Action That Was Later More Well Known in "D.O.A." with game #2 of that series. But that's off topic.)

Point is MegaMan X4 Showed the game development community that 2D is not dead by a long shot. Nor should be abandoned for an idea that is experimental. (Like the "Street Fighter EX" Series and several other unknown games that have graced the "Playstation 1".)

This very website is proof that "2D" and simplicity is not dead nor should be. I think allot of developers should learn from the example of MegaMan by sticking to what works when it works and experimenting when it is the right time and remembering that sometimes less is is more. (Less money spent and more money gained kind of thought.)
Today going "3D" is not too bad an Idea because everyone knows what works and what does not work.
Sadly many of us nostalgia fans are fans more of the experimental attempts that developers where trying out. Some were awesome. others were So So. But Because we had a demo to play before a purchase? We had little to complain about.
Good Times.
Thanks For the Chance to get nostalgic.
I hope you have more to say the next time you submit a review. You already show you have good taste. Good Luck.

Good Luck To All.
I'm done. Stick a fork in me.
Peace.

dre154 : This review needs work. Although it suceeds the review requirements. You really only touched on 1 category and that is storyline. You should consider using other categories And break them down with great amount of depth. As Orionfoxgibson even gave you a good example what to do in a review