Made in Roblox, so you’ll have to sign up to play, or get your kid to play and rate it lol. Signup takes like 1 minute, pretty sure you don't even need to enter an email. Descend through the depths with a team of up to 4 players to defeat Raggy, the Molten Core final boss.

Source Studio project loadable through the Roblox Studio platform, if you’re struggling to get it loaded, feel free to contact me. Opted out of Audio & Graphics, since I just used what was built into Roblox's game engine.