This is one of those where expectations are one of the main determinants of whether or not a certain game is going to feel satisfying for you. Most criticisms I have encountered come down to that. Some of what I'm going to say might sound negative. I assure you, it's neutral. Flight is soothing and never used for anything other than when you travel around an open but empty world. You can't use that at all inside despite some of the inside areas being kind of big and featuring travel and backtracking.
The ending does not deliver all of the things we expect from video games today, but ultimately I would argue it shouldn't. Don't get me wrong, if this cut to credits just 30 seconds earlier I would find it deeply frustrating. It's very much one of those things where they don't give you what you want, but something interesting and unexpected instead. This was clearly a passion Project.
The platforming like everything else about this is never actually challenging. There are no fail states. If you miss a jump you just have to walk and jump to get back to the part that you failed at. Similar for the puzzles which you can brute force if you feel like. And otherwise, the solutions tend to be easy to get to. They're based around jumping, pattern matching, and that sort of thing.
All of these gameplay elements help you appreciate the world that this puts you in, and allow you at least some engaging with it. This game is somewhat similar to Dear Esther and Adios; it's not so much that you are engaging in challenging gameplay as you are moving through a compelling short story. I love all three of these; I wouldn't if they were just a third longer than they are.
The achievements encourage you to explore, There could be more of them and this could also easily have implemented collectibles, if they wanted to increase replayability. Personally, I don't think I'm likely to play this a second time, though I wouldn't rule out going back and taking flight again. A great way to de-stress.
