I would love to know the sales figures. All in all, upon reflection I think it can't be understated just how good the original Prime games were/are. Under a broader context it's a fucking miracle Prime 1 achieved what it did and on the first try no less. It's so hard to put yourself back in the year 2002 mindset, and impossible for those not born yet, but let's look at some hard truths.
In early 2002 Metroid was still languishing under an 8 YEAR LONG coma, it had been 8 years since anyone got a single taste of Metroid, and the last game was the legend called Super Metroid, one half of an entire genre's namesake (Metroidvania) which was still in its infancy at the time. The Metroid brand was given over to a new studio, Retro, which was helmed by a bunch of Texas barbarians who just got done making Turok. Not only was the japanese Metroid series being given over to westerners, they had been charged with making the first 3D Metroid game. Let that sink in, a mid-tier American studio of FPS creators was given the task of revitalizing the Metroid name, after an 8 year coma, following Super Metroid, and doing it via the 3rd dimension. The game should have been an outright failure considering all those variables...
If this thread existed back then everyone would be (rightfully) losing their shit expecting the next Metroid game to be a dogshit shooter made by a bunch of gaijin that completely missed the mark on what made Super Metroid so good................... and yet, it released as a masterpiece.
Somehow a bunch of Id-tier FPS nerds not only nailed Metroid's design, it also nailed its atmosphere, and I would argue it went even further beyond thanks to being in 3D. And on that topic, people need to have a healthy appreciation for just how hard transitioning a 2D series into 3D must have been at the time. All of this shit was new, it was all uncharted territory and EVERYTHING had to be altered in some way to work in 3D. Franchises like Mario and Zelda had to drastically change the way they played while also staying true to the core of what made their originals fun. It was an incredibly treacherous tight rope to walk, and so many series were unable to make that jump successfully... The fact that Retro brought Metroid back from an 8 year coma and into the 3rd dimension so flawlessly, is nothing short of astounding. When people heard Metroid Prime was coming out, they thought it was going to suck. But it blew people's balls off. I'm sure Shiggy's magic also helped, but it's worthy of endless praise either way.
Now cut to Metroid Prime 4, an entire generation removed from the original team that made Prime 1, a virtually new studio when it comes to the amount of old staff remaining. No Shiggy, but 3 amazing games in a trilogy to use as reference material. Coming off a literal remaster of Prime 1 to also use as reference material............... and then we got the fucking mess that is Prime 4. That's a pretty legendary flop. Other M was just as bad but for different reasons. The Metroid series was riding high in 2010 after a decade of classics, both 2D and 3D, only to be met with the utter gut punch that was THE BABY THE BABY THE BABY THE BABY THE BABY THE BABY THE BABY THE BABY THE BABY THE BABY THE BABY THE BABY THE BABY. It was a unique and different taste of terrible... but Prime 4, that's a new level of disappointing. Don't cry that it's over, smile because Primes 1-3 exist and can be played whenever you want thanks to emulation.