The images do justice to the game: this is a typical beautiful, moodie indie game with a unique premise and a sense of discovery and wonder. Great, I loved all of that. It's also very short (I beat it in under four hours) and there's not really any major surprises.
You get your vehicle, you pilot it, you micromanage it a bit ("Wind's up? Put on the sails. Winds down? Take them down and start the engines. Fuel low? Fuel it up, and restart the engines. Oh, gotta get rid of the steam") which feels a bit like busy work to keep you from realizing there's whole stretches of nothing but (beautiful, hand-painted) scenery. Then you run across a few very basic puzzles and then... you're done. Typical to moody, beautiful indie games, it explains nothing, so you're left to just enjoy the imagery and come to your own conclusions.
I feel like the $15 price tag is high. I paid $8 and I feel like I paid too much. That said, I don't think I'd hesitate to recommend it to the right sort of person, though I lean closer to $5 than $10. It feels more like a quick sketch of a neat idea than a full game (and I've played a lot of moody, beautiful indie games in my time).