Use the arrows to control the street cleaner and catch all the tacos. Every taco you catch gains you points, but each one that hits the ground takes points away. Watch for the specially colored tacos! They can win you more points if you catch them, but can lose you more points if they're dropped. Get to level 15 to find the taco at the end of the rainbow.
Updated May 9, 2017 - If this is going to stay in the studio, it should at least meet the criteria I set for these projects, so it is now possible to win this game as well as lose it.