Its big weakness is that they didn't realize how much multilayered backgrounds made things pop.

The sprites look really good, but the single background layer makes things look flat compared to the SNES / Genesis. Devs started working around that by updating some of the background tiles on each frame or using some of the sprites.

The SNES also could do layer blending effects. So while all of the input data could only be 256 colours, the PPU was spitting out a high colour signal after the effects were applied.