The concept is quite cool, and I like the way that mines beep to make them easier to find. The main menu theme sounds terrible (sorry, it does), but the level song is pretty good. I would like to hear a longer loop of it.
The menu looks really good. I like the way day mode, the top of the game's title, and night mode all glow in contrast to the dark, gloomy surroundings. It's very clear what you're supposed to do. I chose day mode first, which was a clever way to make me play the tutorial without labeling it as such or giving me on-screen instructions.
The visual design in-level is also great.- the rocks, mine, rat, and background are all very easy to distinguish from each other, since each has a distinct size, shape, and color. The audio que with the mines makes it fun to hunt them fast. I am not, however, a big fan of the player model or its animations.
Over all, it's a solid experience that left me wanting more.
Three small improvements:
Have the mines explode at some point
Improve the animations for the rat, especially in day mode, where it's more zoomed in on it
Replace the main menu theme, or use the level theme for it too, and extend the loop so it doesn't get annoying after two minutes.