BronzeBobbinVent

Portrait endless ancient bronze pipe. A steam current drives your bobbin up it, so there is no stopping and no going back - the length of a run is decided by how long the bobbin keeps its SPIN. The finger is a place in the bore, and the bobbin slides across to it on its own traction, which is what is left of the spin: a spinning bobbin grips the bronze and crosses the bore in half a second, a stalled one slides. The spin is the life meter AND the steering, and that is the whole game. It falls at DRAIN(t) and falls faster the longer you last, and the only thing that puts it back is the bronze filings the pipe sheds - so the score and the survival clock are the same action. The pipe fires at you. Steam vents are mounted on the walls: each one charges its pressure dial as it enters, you can see which wall is armed from two pipe-lengths away, and then it fires across its side of the bore. A jet does not damage you in the usual sense - it knocks the bobbin off balance: a fifth of the spin meter gone, the grip cut for the next second, and a shove away from the wall it came from. Two vents close together is how a run ends early, and the bobbin that has just been knocked off balance is exactly the one that can not get out of the way of the next. As for what ends a run for a player who never makes a mistake: the filings thin out. From one every 0.62 s to one every 1.62 s, while a filing is worth a fixed amount, so the income per second falls from 1.21 to 0.46 while the drain climbs from 0.320 to 0.760 - they cross at about the 200-second mark and never cross back. Past that even a player who catches every single filing is running a net loss, and all they can change is how late it comes; and since the grip is the spin, the last minute is spent sliding rather than steering. Meanwhile the current runs faster (0.55 to 1.05), so every warning window - which is a DISTANCE divided by that speed - falls from 2.35 s to 1.23 s, the vents themselves come every 2.36 s down to 1.24 s, and the reach of a jet grows from 0.55 to 0.80 of the bore, narrowing the strip of safe wall the whole way up. The two powers: the refractory coat takes one steam blast on the chin and leaves the balance alone, and the draw magnet drags every filing within reach toward the bobbin for four seconds. Endless mode, no fixed stage.