Close the loop, and the lamp lights.

That is the first level. By the seventh chapter a machine you wired listens to a blinking beacon, tells the dots from the dashes, and lights the lamp marked A.

BitWise is a puzzle game about electricity and the machines people made from it. You place parts on a bench, wire them by hand, and the circuit runs on a real simulator. The grader has no answer key. If the lamp lights, current reached it.

Build it once, then build with it

Wire an XOR out of NAND gates and it is sealed as a chip in your tray. Add one AND and the half adder is sealed too. Cross two gates and you have a latch. Discipline the latch with a clock and you have a flip-flop. Line up flip-flops and you have a counter. Every part you build this way is sealed by your hand and carried forward, until the tray holds an ALU and a program ROM and a bench asks for a machine that follows orders and halts itself.

Seven chapters, one engine

The campaign map is the Iron Heart, the engine the whole workshop turns on. Each chapter is one of its subsystems. The map is a machine too, and in the third chapter you build it yourself.

• The Spark. Battery, lamp, switch, and the return path. Rub amber, charge an electroscope, and watch the first spark cross the gap.

• Currents & Light. Resistors, capacitors, diodes, a transistor, an op-amp, a transformer you wind yourself, and the coil that crowns the title screen.

• The Electromechanical Arts. Wrap current around iron and the iron moves. The relay, the burglar alarm, the telegraph relay, a buzzer, a generator with no battery in it, and the motor.

• The Boolean Engine. AND, OR, NOT, then NAND, then everything from NAND. Truth tables you test by tapping a row, comparators, and a glitch you cannot see.

• The Calculating Engine. Read bits as a number, then teach dead metal to add, carry, subtract, and multiply.

• Memory & Time. Turn one wire around and a circuit gains a past. Latch, flip-flop, counter, clock, an address book, and the stored program.

• The Telegraph. Learn Morse by ear, key it by hand on a telegraph key, then build the receiver that reads it for you.

Live current on every wire

Analog benches run on the same nodal analysis SPICE uses. Digital parts settle every tick. Touch any part and the Inspector's Probe reads its live voltage. Put a trace on the Oscillograph and watch a counter tick, or a relay chatter alternating current out of two batteries. The grader watches what the circuit does. A strange build that does the job passes, and a bench that is teaching the relay will not take a lamp lit around it.

One idea per level

Each new idea gets a level of its own before the next one leans on it. Predict the output before you test it, if you like. Hints climb three rungs, from a nudge to the whole build, and you decide how far up to go. The Almanac keeps a concept map, a toolkit of every part you have sealed, and a codex of where it all came from: Shannon's thesis, the telegraph stations that earthed their return wire, the SRAM cell.

Players of Shenzhen I/O, Turing Complete, and Human Resource Machine will know the shape of this. Here the thing you build is a circuit, and it runs. Anyone who has only ever wondered how a computer works can start with the lamp.

At launch

• 223 levels: a 55-level campaign and 168 challenge levels in families like Diagnose & Repair, The Glitch You Cannot See, The Address Book, and The Machine That Follows Orders

• A Sandbox with open benches, a level editor, and Steam Workshop sharing

• The Wireless Room, a Koch-method Morse trainer

• Three-star goals, 14 achievements, and cloud saves

• Every sound in the game, music included, synthesized by the game itself

The game makes no network calls of its own. Your progress lives on your disk and in Steam Cloud.