I've got to applaud your use of the resolution restriction. You've got a platformer that feels really solid. I also love the sound effects. They've got that 8 bit retro charm.
I think the game asks a bit much from the player early on. The initial platforming challenges have you jumping as far as you can over pits of spikes and lava, and I died several times just trying to get to the sword.
I'm not sure I would have picked getting the player's health up as the first major objective, since it would have been nice to have more health while trying those challenges.