I would have preferred the "rumbling" to appear a bit later in the game, maybe in case
- you pick up a collectible -> This way there would either be things in your way you would like to evade but that don´t kill you,
- you reach a certain number of clicks -> This way you would be encouraged to reach as far as possible with as few clicks as possible
Replayability is not too high on this game for me, yet. One reason is that my head tells me "aaaw, in order to beat my highscore, I have to do it aaaall again, and more". Maybe one of the above option would change that thinking to "Aah, if I evade that, I could survive a bit longer" or "Aah, if I click less, the earthquake will trigger later, so I might try again with clicking less/more srategic"
Keep it up!