Currently, there is no way to remove games from Mistplay or from your "keep playing" section.
You are however always free to uninstall any games you would like from your device. All of the GXP and units you've earned from this game will still be associated with your Mistplay account.
This means that If you change your mind and would like to start playing a game again, you can easily find it from your "keep playing" section and resume from where you left off! 🙌
Please keep in mind that uninstalling a game from your device can unfortunately make you ineligible to earn gems from any in-game purchases you make. As per the rules stated within the app, should a game be uninstalled, the player forfeits their right to earn gems for in-game purchases