Ben Ten Alien Force is a good game, but I still think that Ben Ten Protector of Earth is better.
Good
Graphics are great. Especially on the aliens. The attacks that are done look great, and the surroundings are pretty good too.
Cut scenes are done beautifully. It is as if you are actually watching it on TV.
Boss battles are fun to do. They involve nifty puzzles that you must solve, especially when you have to fight Kevin.
Love the storyline. It fits perfectly into the TV show.
Bad
Game is too short. There are only 9 LEVELS!! Sure the levels are pretty long for an average level, but still, 9 LEVELS?! This is basically the reason why I rated this game 7 instead of 8.5
Still a lack of variety on the aliens, you only get to choose from 5 on the PSP version and it isn't that fun.
Overall, I still think Protector of Earth is MUCH better.
Summary
Good
-Graphics are great.
-cut scenes are fun to watch
-Boss battles are fun and involve some thinking
-Good storyline
Bad
-Too short
-Lack of alien choices
-Protector of Earth is much better.