Well made with some really good spritework and animation, especially considering the low res.
Music and atmosphere is also pretty awesome.
If i had to nitpick i'd say that the jumping down mechanic is a bit odd, with having to first jump then press down in the air to go down platforms, and i didn't quite understand some enemies at some point seemed invincible after i killed 2 or 3 of the same type ? (the blue floating ones) maybe a bug i'm not sure.
Regardless i had a good time anyway, and i like how you managed to get the feeling of the whip attack down, and even have the powerups inside lights just like Castlevania !
Neat entry, Good job :)