I just tried with a controller and it's also very bad. The walking is very fast like on keyboard but looking is now super slow. On mouse you rotate very fast, on controller you look very slow. I tried setting my mouse to absolutely slowest mode (Razer DeathAdder V2 Mini). I already use it on one of the slower modes by default. I was able to reach the second level. There was the jumping from the hole. That was another breaking point where I decided to stop playing.
Dark Souls is really challenging game but you still feel like you have your character under control. The jumping feels way too "floaty" and sometimes didn't react properly, walking kinda slides, mouse is limited to what user can set on their mouse, and so on. As a concept it is good but in the first 2 levels I saw a work for one person that can be done in 3 days. You were a team of five (by JAM page) and even thought the game looks interesting and has good music, it feels like an early prototype.
I don't mean to sound rude or throwing your game or your team under the bus but I really tried to play this game and I feel fairly disappointed. Hope the post-JAM version is going to be more playable. Good luck guys.