Castellan (Demo) needs some serious work to become a better game. The idea and core gameplay aren't bad. When I first started playing the aspect of the buttons was all over the place. Lots of things were cut off of the screen making it very hard to play. The 4 buttons at the top right I didn't even know what they were until I started clicking on them. One of those buttons is your inventory which is a big part of the game. The buttons on the bottom right for you to attack and jump and defend are all smashed together making it awkward to try and use.
It's a shame because the game runs super smooth and I love the character animations for attacking and how you can slide down the walls. Which brings me to the next problem and that's the invisible walls and floors. While jumping near a platform your character will just float in midair as if you're on a platform but visually you are not. The invisible walls make you constantly stuck and then seem to randomly disappear allowing you to progress. At one point I couldn't even move forward anymore and then after jumping several times my character magically moved forward.
Overall, I don't reccomend this game. It has too many problems and the buttons being all cut off the screen really ruined the experience for me.