I don't even know. The graphical style is good, but gameplay itself is way too inconsistent and heavily relies on trial'n'error. By itself, it isn't a bad thing, since it was well executed in early Sierra games and stuff like Uninvited or Shadowgate. But again, aforementioned games, despite being relatively brutal in terms of hard puzzles and cheap deaths, had some sense of consistency, but puzzles in Antumbra are all over the place, and so are gameplay mechanics. Sometimes you need to choose counter-intuitive options to survive, but other times it will get you killed; sometimes you have to find a hidden active point on a screen, and some screens later, you find a room where doing this seems an obvious solution, but in reality, there are no objects you can interact with. Combining text and point'n'click adventure core mechanics by itself isn't the best idea, what more can I say. And it's not like puzzles in the game are that inventive or unique - most of the them feel more like a chore, since the only way to find out any solutions in many parts of the game is basically to try everything until it works. Even one of the primary ways to get legitimate hints (grinding maggots for a Tooth Lady) is a chore by itself. There are many examples of great adventure games with a lot of death scenes ("Space Quest" and "Shadowgate" are this turned into an art form) and inventive, original puzzles that require a lot of lateral thinking ("Myst" and "RHEM"). In both ways, Antumbra sadly pales in comparison.
As for the good stuff - I really like the art style, and the atmosphere is good too, even if it feels somewhat cheesy in some parts (cartoonish heart in the ending, an option to whistle in the beginning). I see a lot of visible effort here, and you have a great taste in surreal imagery, and since this is your debut project, I believe that your next games will be better and more polished c: