I've made this game with Godot Engine as a part of the Hour 5 exercise from the book: "Godot Engine Game Development in 24 Hours".  I've been really liking the book so far, if you want to learn how to use Godot Engine, its really in-depth.

Controls:

Spacebar - Select/Fire

Arrow Keys - Move

P - Pause

Asset Attribution

Besides the art assets provided by the book for the exercise, I've used other assets as follows:

Main menu Art: Space Background by ansimuz

BGM: "Step by step" and "In the Monsters Lair" Author: Cedelfelt

SFX: All of the sound effects used were taken from this 512 8-bit sound effect pack by Subspace Audio

Leaderboard plugin: SilentWolf