In some rare cases, a new version of the game could not appear in the App Store or Google Play Store. Here's a quick instruction on how to refresh your device's application store and download the latest version of the game.
Google Play link
App Store Link
Web version Link 
For App Store:
- Open the App Store
 - Tap your profile icon at the top of the screen
 - Pull the screen down and refresh the app list
 - Scroll down to see updates
 - Find Mighty Party
 - Tap "Update" button next to an app to update the game
 
For Google Play:
- Open your device "Settings"
 - Proceed to your App list
 - Find Google Play there and tap on it
 - Choose "Storage and Cache" -> "Clear Storage and "Clear Cache"
 - After that, please access the Google Play Store via the Google Play Store App and search for the Mighty Party update.
 
For Web version:
- Write down or screenshot your in-game ID (ABCDEF), so you won't lose your account
 - Clear your browser cache and cookies
 - Open the game using this link