That's a very nice and polished game :) I really like the retro style and how everything fits together. All the effects and post processing is amazing ;) How did you managed the dialogs (own code or asset?)
I must admit, I'm not a fan of arrow-key controls and always prefer to have the jump button on arrow-up (or W if you go for WASD). In the second level it was a little hard to tell which platform is walkable.