I'm sorry to hear that! But I have no delay... The browser version may be a bit slow. Try downloading it and playing on your computer and lmk if the problem persists!
just tried again as others say there is no delay but for me as i jump over the first hole and press dash it doesnt trigger until ive fallen down the hole and am almost off the screen. the only workaround ive found is to keep the dash key pressed constantly then release it when needed - then you get an instant dash .
also , using a key to restart after a death would be better than having to move your hands off the keyboard and press the mouse ( laptop )