I don't know if I could tell you all the fillers but I'll tell you some.
1. Kazemaru & LAMEndou's moment before Kazemaru quits Raimon.
[In the game, Kazemaru didn't lost hope after their defeat against Genesis. He was the one who was injured, not Fubuki]
2. If you played IE2 Fire, Diamond Dust will be the filler for you. If you played IE2 Blizzard, Prominence will be the filler for you. If you don't have both copies, then Chaos will be the filler for you.
So yeah, the matches against Prominence, Diamond Dust and Chaos are fillers.
3. Toramaru's story. Honestly, Toramaru is one of the WORST character in Inazuma Eleven. He has no personality, his mother isn't really sick at all the time, Nonomi Nashimoto doesn't really exists and he's the weakest striker in the team. The anime producers made him a lame story which turns to be horrible. Because of that, RC Shoot was created.
4. Inazuma Japan vs. Red Matador match.
5. Inazuma Japan vs. Tenkuu no Shito, Makai Gundan Z & Dark Angel
They are in the game but they only appeared after Aphrodi failed to defeat them.
In the anime, they kidnapped Haruna and Rika to sacrifice to the Devil [Which turns out to be the Dark Angel... Makes no sense right? If the story is horrible, that means that story is a filler]
6. LAMEndou's struggle to learn God Catch. Come on... LAMEndou learned God Catch in the game the first time he uses it.
7. LAMEndou Ma-moron and LAMEndou DIEsuke's moment. That was a huge waste of time.
8. LAMEndou and Rococo showing off who's the better man. Rococo and LAMEndou using Double God Hand [A filler technique].
9. The Boring 2nd Inazuma Japan vs Orpheus match.
10. 30% of the anime are fillers.
1. Kazemaru & LAMEndou's moment before Kazemaru quits Raimon.
[In the game, Kazemaru didn't lost hope after their defeat against Genesis. He was the one who was injured, not Fubuki]
2. If you played IE2 Fire, Diamond Dust will be the filler for you. If you played IE2 Blizzard, Prominence will be the filler for you. If you don't have both copies, then Chaos will be the filler for you.
So yeah, the matches against Prominence, Diamond Dust and Chaos are fillers.
3. Toramaru's story. Honestly, Toramaru is one of the WORST character in Inazuma Eleven. He has no personality, his mother isn't really sick at all the time, Nonomi Nashimoto doesn't really exists and he's the weakest striker in the team. The anime producers made him a lame story which turns to be horrible. Because of that, RC Shoot was created.
4. Inazuma Japan vs. Red Matador match.
5. Inazuma Japan vs. Tenkuu no Shito, Makai Gundan Z & Dark Angel
They are in the game but they only appeared after Aphrodi failed to defeat them.
In the anime, they kidnapped Haruna and Rika to sacrifice to the Devil [Which turns out to be the Dark Angel... Makes no sense right? If the story is horrible, that means that story is a filler]
6. LAMEndou's struggle to learn God Catch. Come on... LAMEndou learned God Catch in the game the first time he uses it.
7. LAMEndou Ma-moron and LAMEndou DIEsuke's moment. That was a huge waste of time.
8. LAMEndou and Rococo showing off who's the better man. Rococo and LAMEndou using Double God Hand [A filler technique].
9. The Boring 2nd Inazuma Japan vs Orpheus match.
10. 30% of the anime are fillers.