I remember watching Neco The Sergal's video a bit ago and I love how the game goes but will it ever be free?
There is a free demo, allowing you to go to the third floor, and right now full game is on sale, so you can buy it for a bit cheaper price.
In my opinion, it is really worth buying it, but I would recommend playing the demo to know if it fits you. (but I have to say, that full game is much better than the demo, and that there is a lot more stuff in it)