I tested this game and looks great so far
I don't want to get spoilers so I'm trying to be careful. How many years/releases it's said to be remaining to a fully completed game?
If it will take like 10 more years, I would prefer to spread playing it over a longer time period
Legitimately we're looking at around 10 years for this to be complete. The devs haven't made any estimations (and their predictions for single updates are usually terribly inaccurate) but we can make our own projections, because it's fun!
The current update is focusing on one character (Holly), who already had 1/3 of her 'quests' implemented in the game, and the update is predicted to take 15 months in total. The previous one took even longer (due to incidental delays, but it's unrealistic to expect we won't see some amount of delay for future updates too for one reason or another).
Moving forward we have the following
4 confirmed updates coming;
1) Main Story I part 1 (Lana, Madeline, Maple)
2) Main Story I part 2 (Lana, Madeline, Maple) - These two are confirmed happening next, the order of future ones is TBD
3) Gretta & Anne
4) Joy & The Twins
Then we're likely looking at minimum
2 more Main story updates (covering Serena, Simmone, Simmone's mother) and at least
2 other updates on top of this for bits of remaining characters/content (Mei, Jen, Celestina, pregnancy content for most characters). The characters may end up being in different combinations of updates, and this assumes no new characters are added.
That's 8 updates in total after this one, which is due in 3 months time. Assuming they all take just over a year (which is generous given their new pace), we're actually looking at 10 years.
I will note though, that several individual storylines are complete (minus a couple of potential future group and pregnancy scenes) for a few characters, and if you prefer to play but only engage with complete storylines, the following characters fit this; Myrtle, Rose, Gomira (though her story introduces other characters who are incomplete).