NotEye new speed is awesome!
Loose blood animation is superb! Easily the best effect currently. Hats off to the artist, who drew it, masterfully done! You should aim toward this quality while drawing some powerful, high level spells, like Death Ray: hand drawn - animate most frames, like the drawn explosion frames in Iron Giant.
Hit "red slash" and poisoned effects look nice & useful. Claw/slash animations are excellent!: Maybe increase red outline +1 pixel, because the really good looking tiny blood-drops aren't apparent. I only discovered the cool blood sprays by checking out the PNG animations.
Spell Effects feedback:
Invisibility is best!! Don't touch it, its perfect.
Cure light wounds is very nice.
Burning hands: since it is usually a fire spray looking like this .. player<<monster .. , the sprite frames - while played - should move towards the monster, beginning with tiny flames at the casters hand and gradually increasing sprite size then reaching the monster you can play an explosion: like a short distance flamethrower burn effect in a couple of frames.
1. All explosions - currently spell castings look too much like explosions - should be played at the end of the path of a missile: hitting the target. Currently all bolt explosions are played on the player sprite. Spell release effects should look like a thin soap-bubble expanding around the character, then popping.
Easier to do this with a golden shine, fading in ~ also increasing in size ~ then fading out behind the player character sprite, while the spell projectile itself - for example fire bolt - travels its fiery path and slams into a target then explodes.
It couldn't hurt creating bolt SLAM splashes: like "water splashing" in the spells color around the hit target with tiny multiple spell-splash residues traveling outward around the monster and disappearing.
.. edit: you already have a splattering "Fire explosion" looking good!
2. Magic Missile needs a traveling bouncing sizzling spell energy effect along a path - like the firebolt - to visualize BOUNCE, then exploding it is easy on target. Can you rotate & recolor the fire bolt fire-stream sprite to blue+red or golden color and draw it along a bouncing path?
..edit: I see the firebolt anim, of which a shorter "sizzling-line-of-fire" could serve as a magic missile bouncing stream.
3. Firebolt is very nice! The yellow particle effect - again this looks like exploding instead of releasing magical energy - on the character is overkill. It should be a golden aura slightly expanding from Player_Character_Sprite_Center and fading out there - as the firebolt itself travels.
Misc:
Finding secret doors should display an EYE icon quickly expanding and fading out and give some XP: maybe a floating "+5XP" text?
..edit: current PNG animation format is a good one. It seems you have covered this area well.