Sand Collect Puzzle

Tap a truck, watch it collect the sand, send it off. Then do it again. Sounds simple - but it gets tricky fast. Each truck only takes one color. Some hide their color until the one in front of them leaves. Some are locked and won't budge until you've sent off a few others. Some are frozen in ice. You'll figure them out. Just you, a board full of sand, and that "one more level" feeling. No timers, no lives, no pressure. Play a quick round on the bus, or sit down with it for an hour — either way works.