There is some glitch involving the phazon suit, or it just doesn't count towards your completion percentage. In either case, the last item you obtain counts as 2% (in your case, the final missile expansion).
Actually, unlike you, I have 255 missiles, still 14 energy tanks, 10 power bombs and all 12 artifacts. you are missing two missile expansions and two power bomb expansions.
About 250 Missiles in Metroid Prime.
you find them
Artifacts in Metroid Prime are like Keys. In the game, besides the normal Story line that you have to play, there are Artifacts hidden thruout the 5 maps which you also need to find to unlock the Crater which is the last part of the story. You need 12 Chozo Artifacts (or Keys).
Break open the protective shell with missiles, then plug it in the eye with missiles when it opens its eye.
you have to not get the diffusion missiles and go straight to the navigation room
planet elesia. I don't Know if I spelled the planet right.
Technically he was there from the very first game in the Metroid Prime series (Metroid Prime) since Dark Samus is Metroid Prime. If you get %100 completion you will see her in the end cutscene. But you don't see her humanoid form until Metroid Prime 2 Echoes.
You have to collect all seven Chozo Artifacts (which require specific abilities each).
Try to find as many life tanks as possible. Missiles help too. Charge your missiles to defeat bosses. Good luck!
The easiest way to beat them is to get against a wall, charge the charge beam, and fire Super Missiles at them when they appear. 2 Super Missiles each should be enough
To kill a Chorizo simply shoot it with missiles or the power beam.
im not answering dat well i dont no but still im not trying to b mean or any thing but......do u actually think some1 is going to name all 255 missiles? i mean theres 2 much if u really want 2 no buy a guide or google metroid prime 2 walkthrough