This is the 2D-native counterpart to the 3D bacterial electron-transfer simulator. Rather than orbiting a rendered biofilm, it simulates the extracellular electron-transfer mechanism itself in cross-section: for the direct (nanowire) pathway, each bacterium is wired to the anode as its own resistor, and electrons are sourced from bacteria with a probability set by real parallel-conductance sharing (Σp = 1, checked live); for the mediated (shuttle) pathway, redox-mediator molecules perform an actual 2D Brownian random walk with electromigration drift between the biofilm and the electrode, reproducing the diffusion-limited cap on mediated current from first principles rather than a scripted wobble. Both feed the same closed-form Nernst–Monod current law used by the 3D model, visualised here as a live j-vs-E response curve and a real-time current strip chart, so every slider move is visible simultaneously in the particle mechanism, the analytic curve, and the oscilloscope trace.