Good effort, solid presentation
Nicely done animation. Pacing sometimes felt like it waited just a beat or two too long before moving on in transitionary periods. The lack of sound really emphasized the feeling of 'hmmm... waiting a little bit too long for something to happen.' It doesn't destroy the work, but it certainly detracts from this feeling like a perfected product.
Also, you forgot to credit the Link's Awakening sound team for the use of the boss battle theme for your zombie bit.
Good luck and keep on making flashes.