Hit the green flag or [space] to show parameters. Press [space] key or green flag again or tap on the middle of the screen to start rendering. This is computationally expensive, and run it with turbo mode. See Inside > Edit tab > Turn turbo mode on or just [hold shift] + [green flag click] Render time of full-resolution by multiplying render time of resolution divisor 16 by 256, approximation. It took 13 seconds for me(without forkphorous), which means it would take ~3328 seconds to render it with full resolution. Run it with forkphorus, if you have no patience: (this doesnt have the blank!) https://forkphorus.github.io/#372144443
Just to show @kouzone about the scratch 3.0 blank bug that improves peformence
