Great game! The progression felt verz purposeful and I loved how much content you were able to get from those repeating levels without it fceelign monotonous. As a composer, I loved how the main level tune adapted to the depth of the cave, morphing from a more atmospheric tune to smth rhythmic and how the mission complete tune felt like an accomplishment.
Minor criticism: Game feels really pushed on a technical level and not much like a true NES game. Minor quibble though, considering I´d even pay a buck or two on steam to jam this one for an evening.