this is one of the most competently made games I've seen for a long time on this site.
all the neat ideas thrown into this game are decently executed and work perfectly with the excellent level design. the music is catchy and atmospheric, the graphics are nicely pixelated and everything here gives that old NES vibe to the game, and that is really impressive since this is your first game. But the controls need a bit of polishing. every movement has a slight delay and that makes using the sword more annoying, the grappling hook nearly impossible and stopping in place on very small platform mostly results into dead. these are problems that really sour up an otherwise phenomenal.
but you did a fantastic job nonetheless.