It's a really fun game ! I love the progression mechanic, along with the difficulty slowly increasing, it really make you wanna rush for theses dice shards x) The bat scream that make you loose all of your shard is such a clever design idea too !
On the downside, I found the window a bit small, I'd with I could see further. Also, the bullet shooting enemy don't show any sign whatsoever that they are about to shoot (like a glowing red light on their head right before shooting). The bullet just spawn, rushing straight at you. It make it quite frustrating, because you can never ever be too close to them, they could spawn a bullet at any moment.
Overall I really enjoyed finishing this game, great work !