I was never a huge fan of the show as a kid all because of my stubbornness but I remember people playing that game in free trial in a game store before.
Ben 10 Protector of Earth is every kid's favorite game mostly boys in the 2000s and honestly, this game is not that bad at all.
The graphics were very decent for a PS2 game. It looks exactly like the cartoon but only in 3D. The gameplay was straightforward but good enough to fight off enemies. And the voice acting remains decent and great because they still reprise the roles in the game.
The bosses in the game were a bit decent. I just kind of wish this almost plays similar to the God of War games to have more amazing quick-time events.
However one of the cons that this game has is that this does not let me play at least 10 alien characters as I progressed in the game. Just only 5 aliens because what is the point of Ben 10 if it won't let me play 10 aliens? Although the story of the game was already explained why it still won't let me play at least 10 because it would have more interesting level designs.
Ben 10 Protector of Earth is decent enough game to play. And it's is more enjoyable if you watch the Ben 10 classic cartoon series.