RetroArch Web Player

Resize canvas Lock/hide mouse pointer
Enable V-sync (can only be done before loading game)
Enable SDL2
Audio latency (ms) (increase if you hear pops at fullspeed, can only be done before loading game)
Controls:
A button (OK in menu): X
B button (Back in menu): Z
X Button: S
Y Button: A
L Button: Q
R Button: W
D-pad: Arrow Keys
Start Button: Enter
Select Button: Shift
Toggle Menu: F1
Fast forward: Spacebar (toggle)
Slow motion: E (hold) Save state: F2
Load state: F4