Start recording has to set up its encoders first. It asks the browser whether it can encode H.264 at the size and hooks in the sound tap, both asynchronously, and it only took its size at the first frame. Meanwhile the game ran on unrecorded. A caption that fades in from alpha 0 at the start was already visible in the first recorded frame. - A run now waits while a recording sets up its encoders, at most 3 s, as it already waits for its videos at Play. That holds in the editor and in play.html. - The recording takes its size at Play, right after the game view has the world, rather than at the first frame. A Start recording in On start is so ready before the first tick. - A recording started in the middle of a game holds the picture for that moment. A sound that already plays goes on. Tests: - tsc, eslint, Prettier clean - e2e 67 on melektaus-atx: ALL PASSED, 11 checks (67a-ii new). The first recorded frame is at game time 0.0168 s, the first frame. - Without the wait 67a-ii is red: the first recorded frame is at 0.1667 s, so 10 frames were lost. - Gate on melektaus-atx: green, 305 files, 4740 tests, run on this commit and the one before together. - Not checked in the browser: a start in the middle of a game, and play.html. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>