Alright I did some research, although take it with a grain of salt since I never heard of Phaser before just now!
Basically when I open developer settings in chrome and throttle my cpu speed (this lowers fps as far as understand), the game runs normal with higher jumps and playable!
The reason probably is due to you using not the right deltaTime? (deltaTime being the time elapsed between two frames, like if you say you move something 1 unit in 30 frames per second, it will use 1/30 each frame, where with 60fps, it moves 1/60, resulting in both that the object moved the one unit over the 1 second interval)
This link seems to describe the same problem, while this link describes how to slow down Chrome.