When designing your game, learn from the most popular and iconic mobile games like Angry Birds - limit text. Let your graphics tell the player what to do.
Use no text at all or as little as possible to make your game open for a bigger audience. This way you won’t need to translate the game to different languages in order to reach more players.
If you need to add texts and your game does not require to a specific language, use English.
Usually it is impossible to avoid texts, especially for mini game names and promo screens of mini games, try to make them short and very clear.