Robert Rodriguez's charmingly low-tech fantasy, similar to his Spy Kids 3-D: Game Over and written with his son, Racer, forsakes obvious 3-D effects for puns and literalized metaphors--a Stream of Consciousness flowing through a land of milk and giant cookies, a Train of Thought that keeps jumping off its tracks, a thundering brainstorm. They're all located on the planet Drool, where the imaginative kid hero (Cayden Boyd) accompanies the title characters on their quest to defeat Mr. Electricity (George Lopez), a dreamlike version of the boy's bossy grade school teacher. This gets a bit preachy in its defense of imagination, but its homemade, anticorporate spirit--Rodriguez's trump card ever since El mariachi--gives it energy and grit. PG, 94 min. Reviewed this week in Section 1. Century 12 and CineArts 6, Chatham 14, Crown Village 18, Ford City, Gardens 7-13, Lake, Lawndale, Norridge, River East 21, 62nd & Western, Webster Place.