Team Meat's upcoming game, Mew-Genics, will feature side characters that rotate out based on the time and day of the week, co-creator Edmund McMillen announced via the developer's blog.

Each character will play a different role than Mew-Genics' main cast, introduced shortly after the game's announcement. According to McMillen, secondary characters could offer players something or perhaps "help you break into the cat genetics lab." Some characters will never actually appear in-game, but will only interact with players through letters.

"Most of these new side characters will appear and ask something of you," McMillen wrote.

McMillen also adds that the game has also taken "one final sharp turn" in development.

Mew-Genics, announced in 2012, is being developed for Android, iOS and Steam. A release date has not been announced.