Far from a problem and more of a quality of life thing I find the lack of feedback for interrupted castings very annoying. There is feedback for the readying of a spell but not for those spells that are interrupted by enemy attacks. I've eaten a boatload of hits that ultimately lead to the ending of a run because I thought I was able to cast a spell that was on cooldown all because I didn't realize the casting was cancelled by enemy damage. It'd be really really nice if there was a visual feedback to communicate a wasted cast.