It's the fusion between Portal and The Stanley Parable. I lack a bit of perspective for not having played the latter, but the game is pretty cool; I haven't played anything quite like it, to be honest. I lower the score due to some flaws in UX design. I understand that part of the charm of the game is not telling you things, but it contradicts itself in some design matters. There are times when you also have to restart the level due to mistakes or bugs. However, it had me hooked all afternoon, made me rack my brain, immerse myself in its world, suffer, and even the final message moved me quite a bit. Very intriguing and recommendable.