Runs bad on the LG G4 in Chrome but better in Firefox. Iphone 6 aces it with Safari but noticeably slower with Firefox. iPhone 6 res is 1334x750 and the G4 res is 2560x1440. My i5 laptop is a little slower than Firefox on the G4 but much faster than Chrome. http://madebyevan.com/webgl-water/
My cheapo Moto G first gen didn't do too well. My 3 GHz (Base) - 3.9 GHz (Turbo) quad core i5 on the other hand, ran super smooth on Chrome. I am still one of those people who uses my phone for nothing much more than calls + WhatsApp with the odd bit of web browsing or Twitch/YouTube. Don't see the point in upgrading although my wife may replace her N5 soon so I may use that.
My i5 is the Ivy Bridge 2.7 - 3.4 MHz 3340m with HD 4000 graphics. I'm surprised it doesn't do so well. Of course there is so much background stuff running that memory hovers around 80%. That might eat into the GPU performance.