the rebirth system need to be reworked because i find it not worth it to even rebirth, so you could let players bring a item over or buff the stats even more.
You activate 20 fragments after first reborn. This makes you twice as strong, because every main stat increases several sub stats. It means if you have 10k power without fragments, you will have 20k with 20 fragments and same equipments. Also you get 20 skill points and can upgrade couple of you skills that makes you even stronger. In addition you keep all your collected knowledge and can run through first worlds really fast.
the browser could not allocate enough memory for the webGL content. if you are the developer of this content, try allocating less memory to your webGL build in the WebGL player settings. that what i got when the game did not work
Nice suggestion, also you can click the icon next to the "Mute" button to turn off some particle effects and reduce lag.