I wonder if they tried running the game at 256 pixel-wide resolution.
I also wonder if millions of copies of early SNES games were returned because they didn't run at normal or consistent speeds.
I hear you.
I actually like Gradius III on SNES, but that game was soooooo sloooow at times that I honestly wondered if it was about to eject itself from my SNES!
How many returns did Gradius III have?
Instead of returns, the SNES only spawned the first generation of Nintendo zealots like A Black Falcon, who reverse engineer reality to claim that Super Gradius III is the best and definitive version and that when slowdown happens frequently enough, it becomes the new standard and is in fact creating new and superior gameplay experiences. I really wish that was sarcasm and not literally a sampling of ABF's cross-forum preaching over the years.
If the SMS had been about as successful as the NES in North America, we would have had these guys a generation earlier. But the SNES not only being the first Nintendo console with real competition, but coming in late to the party and underperforming out of the gate, led to the first generation of console fanboys since perhaps the pre-8-bit generation. The Nintendo 64 following right after under similar circumstances but lacking the quality library of the previous Nintendo consoles, only hardened their resolve.
It's unfortunate, because I find that most blind fanboys don't really appreciate the SNES library and spend most of their time defending its lackluster games or praising the typical top game list entries, instead of discovering all the great games that receive little fanfare, which they are completely oblivious to.