OK, I recognized most of the first half of the characters, but the second half was mostly ones I haven't seen before. I got:
1) Kaoru and... I forget their names (Zettai Karen Children)
2) Hayate (Hayate no Gotoku)
3) Negi (Negima)
4) Natsu (Fairy Tail)
5) Lucy (also Fairy Tail)
6) The dude from Kekkaishi (dunno his name)
7) I think this is the guy from Air Gear (dunno his name, either)
8) Kenichi (History's Strongest Disciple Kenichi)
9) The chick from Kekkaishi (dunno her name either; never actually watched the show more than like once, but I recognize them)
10) Dunno
11) Takamura (Hajime no Ippo)
12) I KNOW I've seen this kid with the green hair before, but I can't remember for the life of me what show he's from
13) Miu (History's Strongest Disciple Kenichi)
14) Ippo (Hajime no Ippo)
15-17) Dunno
18) Inuyasha (durrr)
19-27) Dunno (that's not Guin, btw, Guin has a leopard mask and doesn't wear wrestler tights LOL)
28) Somebody from Cyborg 009 (I recognize the character design)
29) Dunno
30) Mechazawa (Cromartie High School)
This game automatically gets massive bonus points for having Mechazawa in it. Seriously, it does.

Anyway, that's 10 where I knew the name and show, 1 where I knew one of the names and the show (cause there were three chars and I could only remember Kaoru), 4 where I got the show but not the name, and 15 I didn't recognize at all. Not bad, I guess, considering that a bunch of these are probably chars from manga that I haven't read and that have never been made into an anime (meaning I would never have seen them at all).