It sounds like you’re referring to "My Singing Monsters: The Lost Landscape," which was an early prototype / tech demo for what would eventually become the full My Singing Monsters game.
The combined sound wave slammed into the stone. my singing monsters the lost landscape
Future Updates
Enhanced Mechanics: The project introduced crafting systems using island resources and included a variety of mini-games like O Stacker, Thumpies, and Simon Says. It sounds like you’re referring to "My Singing
Updates and Expansions:
Despite its commercial failure, The Lost Landscape changed the main My Singing Monsters game forever. my singing monsters the lost landscape