How the river works
Set an angle and power, then launch. Currents push only while you’re inside their marked bands: sideways, or along the river with you or against you. More arrowheads mean a stronger current. Rocks sink the boat, so aim around them. An eddy pulls the boat toward its centre and spins the water round it; pass wide or fast, because its dark core sinks the boat too. A barge crosses the river and back on a steady rhythm and sinks the boat as well: watch it, and launch when your line will be clear by the time you reach its lane. Two barges that share a lane travel as a pair, with open water between them. A lock wall crosses the river with a gate whose two leaves swing open and shut on a steady rhythm; the wall and a shut gate sink the boat, so reach the opening while the leaves stand open. A log boom is a chain of floating logs anchored at both ends: it never sinks the boat but glances it off like a cushion, taking some of its speed, and a glance mirrors your aim. A small dot on your path marks each glance.
Tap Brake once to slow the boat. You deliver when the whole boat enters the striped dock gently. Miss it? Retry instantly and adjust your aim.
A floating parcel is optional. Collect it on the way to the dock for a bonus stamp. Each delivery can earn three marks: first try, a gentle landing (into the dock at under half the allowed speed) and the parcel. After a miss, the dotted line shows the path you took and where you braked. There is no countdown; the splash, knock and chime sounds can be switched off with the Sound button.
Keyboard: Click the river or Tab to it. Left and right arrows aim; up and down arrows set power. Space launches or brakes, P pauses and R retries. The sliders and buttons work too.
Leaving the tab pauses a trip. Resume when ready. The route ends at the last dock; you can revisit any course to improve your fewest-launch record or collect a parcel.
