Test: Reflection's free 501B Beam model built a kart racer in under 4 minutes

A developer tasked Reflection's open Beam model (501B parameters, 23B active, Apache 2.0) with building a browser-based kart racer with no human help. Beam finished in 3 minutes 57 seconds across 40 steps, but the game had inverted steering and a broken banana item. After one note, it fixed three bugs in 66 seconds.

• Beam: 501B parameters, 23B active, Apache 2.0 weights, free in beta
• First build: 622 lines of code in 3 minutes 57 seconds over 40 steps
• Terminal Bench v2.1: Beam scores 80.1 vs DeepSeek V4.1 Flash at 90.6
• Claude Opus 5.5 took 14 minutes 47 seconds and $2.44 at API prices