Foamstars support multiple languages when it comes to voices. To see how you can switch between them, you can take a look at this tutorial from Seeking Tech.
1. To start off, you need to be in the Title Screen. If you aren’t, exit your current game to return there.
2. From there, select Options.
3. Make sure you are viewing the General tab and then scroll down to Voice Language. You should see the following description:
Change the language of in-game voices (can only be changed on title screen).
4. Select either Japanese or English.
5. Back out of the Options menu.
6. When asked if you want to confirm the change you just made, select Save and Close.
You should hear the new language when you start playing Foamstars again.