Cyprian wrote:just impressive
how many memory is needed? 512kB will be ok?
and how %CPU is free?
It runs on a 520. Though you might have to Auto-Run into it.
It takes just over 1 frame to redraw all the scrolling. And it's the full 320 pixels wide. Even the Amiga one is clipped to 288 pixels. That leaves loads of time in the second frame to draw sprites, of which the Amiga only has two on-screen anyway. And the main character actually has twice as many animation frames as the Amiga! In total what you see is taking about 1.5 frames to render.
You could maybe do it one frame by shrinking the view, but then you'd need twice as much pre-shifted scrolling!
I did have some ideas on reducing the memory usage, such as narrowing the background mountain graphic to 256 pixels, and adding a few extra scenic chunks that can be pre-shifted dynamically into one more slot. So as long as they're kept far enough apart so the routine has time to swap them over, you could add one-off features like the well, the Home tree, statues, etc.