I had a 2D (top down) racing game running on Twitch a while ago. It was basically an endless game where you had to avoid incoming cars by changing lanes. Before an actual car spawned there was an indicator showing the lane, so the player had some time to move out of the way.
I figured out that roughly 5-7 seconds delay worked for the game if you want people all over the world play it. Phone users told me their delay was a lot higher. That was in 2018, so maybe it already changed.
What I’m trying to say: you can have the delay as some kind of challenge. Make it a gameplay element. 
There’s still a test video: https://www.twitch.tv/videos/334042646