Performance was fine for me and I am on a dated machine (Lenovo Z560) running Firefox with about 20 tabs open.
I discovered this game some time ago, from the CopperLicht engine home page[1]. I am a web-developer by day and an amateur 3D designer after dark, looking to build something similar. If the creators of End Time are here, can they (or anyone with experience in this domain) share some insight about the development process, especially procedural world generation?