Thank you for playing! <3
Full game will let you freely configure keys, however, NumPad for these kinds of roguelikes with diagonal movement are actually optimal; might take a while to get used to it, but it's not so bad.
MouseControls will unfortunately not be a thing, sorry. There's a certain mechanic in the game, which is teased at on Map 3 in the Demo, which wouldn't work at all with MouseControls.
The insta-kill tiles (pits and spikes) are a left-over from the original game "Die Gemäuer von Kalawaum", which this is based on. Mind, that I nerfed a lot about them, e.g. a first time warning, and an successive survival roll for a chance to escape unscathed. :) However, they will stay the way they are ... I like the sense of danger and the stakes the bring with them, when exploring unknown grounds.
Have a nice week, cheers!