yea pretty good looking considering the pc engine is really a 8bit console i know it has a 16bit graphics chip but the cpu is 8bit who would think you would see 3d rotating polygon sprites on a console from 1987.
Bits have never meant anything when it comes to consoles. The SNES cpu is mostly 8-bit. The Intellivision has a 16-bit cpu. The Xbox has a 32-bit cpu.
The PC Engine cpu is twice as fast as the SNES and about as fast as the Genesis, but even that doesn't tell the whole story. Bad games don't show you what a console is capable of either, but good ones can. There are hundreds of PCE games that would be very impressive on Genesis or SNES.
3D polygonal sprites, scaling, rotation, and other effects had been done on PCE and Genesis for years. There are two real-time polygonal TurboGrafx-16 games and a ton of impressive ones for Genesis. But the Gameboy, NES, SMS and Game Gear all have 3D texture mapped, shaded, lit, high polygonal sprites which twist and rotate and spin around in all kinds of ways. Donkey Kong Country for Gameboy is the most obvious one.
What is impressive about Sapphire is everything. The number of sprites filling the screen, 2-player gameplay, parallax, overlapping bgs, animation, artwork, etc. Somehow the developer lined everything so that slowdown and flicker aren't a problem.
In the meantime, until you familiarize yourself with the PC Engine library, here is a quick way to see how well cross platform PCE games hold up-
http://www.pcenginefx.com/forums/index.php?topic=6609.msg129420#msg129420Here is how the PCE and the Arcade Card (topic of discussion) compare to the SNES-