Unusually for an NES game, nearly all music and sound effects are stored as high-quality 8-bit DPCM samples directly from the original mobile game. Modern Updates & Fan Projects
In the spirit of old-school bootlegs, losing a level doesn't just show a sad bird; it displays a poorly translated "Engrish" taunt "YOU ARE FAIL! PIG IS WINNER!" accompanied by a terrifyingly low-res image of a pig. for the sprite limitations or a full level list based on these mechanics?
While it lacks the complex physics engine of the modern versions, the level design offers a unique "retro" difficulty. How to Download the Super Angry Birds NES ROM (Updated)