The gun is a frog in Frogun, a game about a frog who is a gun, and also your best friend

pcgamer.com:

Renata's parents, eminent explorers both, have gone missing in the Beelzebub Ruins, and after waiting for three days she decides to strike out on her own to find them. To help her along the way, she takes her parents' latest invention: The Frogun!

Frogun is an old-school exploration-platformer inspired by games of the PlayStation and N64 era. Players will explore colorful, pixellated ruins, rendered «in a modern representation of the low-poly aesthetic,» each of them filled with levers, buttons, enemies, traps, secrets, and collectibles. 

Central to your travels is your friendly Frogun, an amphibious grappling gun (those sticky tongues are incredibly versatile) who will help you navigate these strange ruins, find shortcuts and secrets, and uncover «an extra layer of lore» in hidden exploration notes.

The frog—that is, the Frogun—is also quite smart, and will share thoughts and let you know about potential challenges ahead. That's a handy friend to have in a dangerous place like this.

We haven't had a chance to play it yet, but Frogun is undeniably cute and really looks set to nail the the vibe of the N64 era. We should be getting a better look at it soon: A release date hasn't been set, but it's slated to arrive sometime this summer on Steam(opens in new tab).