The control scheme is a bit weird. Eventually I found my preferred style by running backward and use the mouse to turn and shoot enemies. Backward jumping Super Mario 64 style! :D
The global mechanics are solid. Shooting enemies is fun enough, and the difficulty is balanced. The dice determining which monsters will spawn is interesting. Although I regret there is no interaction with them. As it is, they could be replaced with a text on the screen and the game would work the same, they're mostly esthetic. Also, unless I misunderstood what the faces meant, I wish they would have provided more information by being something else than traditional dices. As it is, a "6" doesn't tell me much about what's going to happen. There could have been symbols more related to the game.
Another strange design aspect is that, once the player has no bullets, there doesn't seem to be a way to gain new ones? It's kind of a frustrating soft-lock situation, which can happen easily given that the monsters take a lot of damage to be defeated, and the gun is short ranged. Or I'm just bad at aiming, that's also a possibility.^^' The game could use a bit more of feedback on damages (either on ennemies, or on the player)
That being said, it was still fun to play! The presentation is nice enough to make the game enjoyable, and the randomness gives a nice element of surprise. For a genre that can quickly get frustrating, your entry has a good balance of challenge without feeling too easy. Nice job!