This is a really good game !
-Art, camera movements and SFX feels very smooth.
-When i look at the pixel art of your game, it's like there are 2 differents style :
-A one with different shade of colors for textures and backgrounds and a simplier one with almost solid colors for the players, ennemies or even the fountain.
-From my standpoint, these two styles are not normally suited together, but the fact that you managed to put a smooth animation for almost every element, makes the whole graphics coherent from start to finish, and final result looks really great.
-The music and the SFX are really good. Modification of sounds like when you get hit really add to the action of the game.
-The gameplay is enjoyable, each area looks different which is nice (the 3rd one is really good), the lighting is well done, bosses are fun and details like the snowmen melting after being hit by fire is apreciable.
-I would say that the enemy projectiles can sometimes be difficult to see due to the large number of particles, particularly during the first boss encounter, but the overall is very good, for a month only it is really well done !