This is awesome feedback, thanks so much! Just today I've implemented keyboard support for the UI. Adding the ability to move diagonally without a numpad is definitely another priority on my list, thank you for the suggestion!
The crash you experienced is probably caused by either an input bug or the enemy AI getting stuck in a loop. Both issues have been fixed for the next update (coming soon)! Super glad you like the concept, I know it's a bit niche but I hope that as I add lore/story elements to the game that the story will shine through. Cheers!