That's what Nintendo does, and it seems to work out pretty well for them.
Why few other publishers have a "Mario Party" or "Fire Emblem" to release in betweeen more expensive titles is beyond me.
Because "Mario Party" and "Fire Emblem" are genre kings, that is game series that popularized a kind of genre/sub-genre decades ago and that are perceived as the face of the genre/sub-genre thus attract most of the fans attention.
They aren't just smaller budget games that copy existing templates.
Creating new concepts that provide an unique identity with the appeal to attract a relatively smaller audience than AAA games but big enough to mark it as a success due to lower budget employed is the hard part.
Then comes the second hardest part that is to iterate the unique game concepts that characterize the franchise generation after generation withouth significantly losing consumers attentions over time.
Nintendo makes it look easy what is in reality very complex because they are very good at it and they are very good at it because they envisioned this path based on originality and fun novel concepts decades ago.
Excerpt from Hiroshi Yamauchi's presidential message 1998:
In the year just ended, we witnessed the expansion of so-
called "next generation" video game systems into millions
of new homes around the world. Indeed, these machines
will surpass the sales of any preceding era of technology,
and their near-term success is assured even when we
have not yet realized even half of the eventual retail sales
for these "next generation" products.
But in fact, the biggest success of our industry in the year
just passed is an appropriate lens to help see the future
and is occurring on a technology that's now more than 10
years old - Game Boy. This simple hand-held, portable
system became home to a new game concept, Pokémon,
which already has sold through more than 8 million games
in the Japan market alone. To sell at such a rate, and to
rinvigorate the Game Boy platform in the process, there
must be something vital at its core. And there is. It's called
innovation.
Pokémon created innovation in an important way. Not by
the look of the graphics or the license of an entertainment
star, but by altering the experience the player has with the
game machine. The innovation of Pokémon lies in its
ability to combine four different attractions into a single
new game experience: training, trading, collecting and
adding. These dynamics individually have existed in other
products. But by combining them into one new video
game experience, Pokémon not only created a new mass
market for these games, but also expanded that market to
toys, television, trading cards, stuffed animals and audio
CDs. It innovated.
Our ongoing goal:
to innovate for the purpose
of creating new game
play experiences.
To alter interactivity.