Very good level design and platform movement! I think you nailed the parameters (gravity, acceleration / deceleration, speed, jump height, etc), which I believe helped you to play around with the gameplay mechanics in a more creative way, making a simple experience very satisfying — for instance, having the player fall then double-jump to pick up coins in some particular spots, which is not something we see too often in this kind of game.
The pixel art is great as well, very charming, it definitely matches the mood and the action.
The only nitpick I have is with the controls / input — I think for any platformer it's better to have the jump button somewhere else in the keyboard layout, not just in the "W" key. I understand this is mainly personal preference, but it can't hurt to give the player options (and since you use Construct 3, it's super easy to implement).
Great job, especially for a first game!