Is this name too strange for my protagonist?

You can name your character anything sweetie. Just like parents can name their children anything. -_-

Anyway, if you're going to name your alien character Allyzon and it's a play off Allison, you can even make a joke out of it. You can make the alien hear the name Allison but they won't spell it properly and take that name for themself. You get the idea. A fun name makes for an interesting character. It will make your characters stick out. You don't want to name your character something normal because then the reader will think of the first person they know with that name and not your character. Original names are good. Good luck!

...If they're an alien, then their name would be most easily encoded as "Sustained period of flashing green light, followed by occilation between various shades of brown, followed by a dim, pulsing red for exactly eight and a half seconds". The thought that a species could evolve complete seperately from humans and not only come about vibrating air to use language but also have a name that sounds almost exactly like a common American name is...

it's ridiculous, is what it is.

If anything, it's not strange enough for an alien. It sounds cute, though.

Keep it, A) because childhood dreams rule, B) Don't question the characters you know best, it's magical when the writers have faith in how they present their characters, C) I don't find it at all weird, and D) the name sounds better than the normal one, gives your story character!

Well, it looks weird and kind of like a person from a different country wrote it. Maybe change it to Alizon or Alyzon.

No, I've seen weirder character names on humans. I think it's very cute for an 'other worldly' girl.

Looks ugly.

I think it's awesome!