1. A red truck can pick up a blue package, but must drop it off at some chosen intersections for a blue truck to pick up.
2. A white truck can pick up and deliver any color.
3. No truck can carry more than 3 packages at the same time. Along with this, say a white truck picks up first a red package, then a yellow one. Since the yellow one is on top, the truck must pass a yellow house before a red one.
4. A skateboard is like a white truck, but can travel on the grass.
5. Switches along the roads will open and close the drawbridges.
Right now there are 360 levels. More may be added. A lot of them are very easy. And a bunch are hard. If you are a loyal reader of this blog, you know that I want to solve as many as possible (ideally all of them) to truly evaluate the game. But 360 is far too many! At the moment I've solved about 240 levels.
Bottom Line: RGB Express is highly polished, has easy levels for kids and very difficult for the pros too. RGB Express is a likely contender for a PAGY Award (Puzzle App Games of the Year).