How do you unlock infiniti aliens in be10 alien force wii?

To unlock the Infinity Aliens in "Ben 10: Alien Force" for the Wii, you need to complete the game and collect all the Omnitrix pieces. Once you've gathered all the pieces, you can access the Infinity Aliens by selecting the Omnitrix and then pressing the corresponding button to transform into these powerful forms. Make sure to explore all areas and defeat enemies to ensure you've collected everything needed for the unlock. Enjoy your gameplay!