When Pokemon Sword and Pokemon Shield launch for the Nintendo Switch this fall, the number of Pokemon species in all of the games combined will total more than 1,000. That’s eight generations of Pocket Monsters over the past 23 years, but that neverending addition of new creatures does have one negative consequence.

In an interview with Japanese video game magazine Famitsu, Game Freak producer Junichi Masuda revealed that not all of the Pokemon that have appeared in previous games will be found in Sword and Shield. The sheer number of Pokemon in the Pokedex has made it likely that no mainline Pokemon game will ever feature all 1,000+ Pokemon, as it would require too many resources and make balancing them all nearly impossible.

That’s the gist of Masuda’s answer, but here is a translation of his quote from Reddit user bte234:

Thanks to Nintendo Switch, Pokémon becomes more lively and has better graphics, but on the other hand, it also takes more time to develop.

The total number of Pokémon will exceed 1000, including new Pokémon and form changes of existing Pokémon. As a result, it becomes extremely difficult to make new Pokémon play an active part and balance them, in addition to upgrading the graphics and quality for the change in hardware and battle. That is the reason for this decision, and we have decided that it is extremely difficult to make all Pokémon appear in future games.

Masuda also noted that he was sad to have to make this decision, but admitted that he was going to have to make it “sooner or later,” and that he is more concerned with the quality of the game than the quantity of Pokemon contained within. The good news is that Game Freak has yet to decide whether or not it will add more Pokemon to the game via future updates, so there’s still a chance the missing Pokemon could return.