If you are celebrating the first anniversary of the launch of a game, the 100th day, or even the 2.5(!?) anniversary of a game, celebrate it as soon as you can. If there is a good time to celebrate, celebrate it actively.
At these times, we can offer various initiatives such as “special login bonuses”, “10 free gacha draws every day”, “halving the stamina required to progress in quests”, “doubling the amount of experience gained” and so on.
By making a big deal of it, we can make people think, “Oh, it’s been a year since the game was launched. I only played it for the first three months, but it seems like a good deal if I play it again now, so I might give it another try.”
If the game is well-loved, players can expect to pay more than usual for it out of a sense of support.