Foundry-5 is a free browser puzzle game that teaches you real RISC-V (RV32I) assembly
language — not a toy or pseudo-code, the actual 32-bit instruction set. You play by
writing bare-metal firmware to bring a dead automated factory back online, one system at
a time.
Each puzzle hands you a small machine — an LED, a sensor, a frame buffer, a motor — and
asks you to make it work by writing assembly. Your code runs on a built-in RISC-V CPU
emulator with a live view of every register, every byte of memory, and every instruction
as it executes. Watch the machine think, step by step.
What you'll learn
- Registers and how data moves through a CPU
- Memory: loads, stores, addressing, and buffers
- Loops, branches, and control flow in assembly
- The calling convention — functions, the stack, recursion
- Bit manipulation: masks, flags, packing and unpacking
- SIMD / vector instructions and real codec kernels
- How computer architecture actually fits together at the lowest level