We might tut-tut violent video games in polite company and publicly yearn for more thoughtful and refined interactive experiences; but in the privacy of our own homes or subway seats, we enjoy good old-fashioned violence as much as anyone. Two-man design crew Bit-Blot knows this and gives iPad players a taste of both worlds with Aquaria.

For 45 minutes, it's a blissful and nonviolent tale of a singing mermaid gliding gracefully through the sea. A few minutes later – right before you fall asleep – the game gives you laser hands and lets you fry evil octopi and other sea scourges with deadly energy blasts. It's cute and PG-rated violence, but violence all the same.

If Aquaria doesn't feel like the typical iOS game, that's because it isn't: this port of a 2D side-scroller released for PCs in 2007 is more Metroid-like compulsion than Angry Birds addiction, with a focus on exploring a labyrinth of underwater caverns. Along the way, you'll slide and tap the screen to make your amnesiac mermaid dash through the water in search of her past.

In a nod to The Legend of Zelda, you use music like other games use magic, as your mermaid triggers certain skills by singing songs, and simple melodies are played by sliding your finger along an eight note, color-coded scale. These songs affect the environment and change your hero into various forms found throughout the game, which also open up previously inaccessible areas. It's a relatively lengthy adventure with story progression, a beautiful score, and lush and colorful backgrounds. And while your hand might occasionally block the notes when you're trying to sing, Aquaria is otherwise a breezy new take on an evergreen genre.

The bottom line. Aquaria feels like a forgotten 16-bit classic in the style of Metroid, albeit with touchscreen controls.