I tried to run tetris using last trunk version of pas2js & Lazarus 2.1.0 but still with error in utetris.pp, in onClick event handler:
function TTetris.DoMouseClick(aEvent: TJSMouseEvent): boolean;
error is located in line 630:
S:=aEvent.currentTarget.ID;
it needs to be corrected this way:
S:=aEvent.currentTargetElement.id;