This is extremely impressive technically and gameplay-wise and proves that, in the hands of a crafty programmer, the simple A500 was capable of pulling a proper Sonic clone. We can only imagine what a A1200 would be able to pull off!
How unfortunate that this game wasn't finished. I reckon that adding more levels, menus, music and sound would "weight" the game down a bit and I also agree that the backgrounds deserved at least some different colours (this sort of game looks always better when there are plenty of primary colours on screen). But what we get to see from this simple preview is already very impressive.
Owing to the Sonic-craze that, as many of you probably remember, was very palpable back in the day, Blaze would have made it big on the Amiga had it been sold as a finished product.