Click on your runes on the bottom left to see what they do and use them to defeat the enemy without getting defeated yourself. Combat is done in turns. After all turns are exhausted the round ends and runes are reshifted. A single rune can be locked between rounds.
This is an improved version of the original Ludum Dare game but it is very far from finished or where I want to take it. I've started probably 5 or 6 full rewrites of this and none of them have gone anywhere. I think one of the biggest issues with this game is that the rules are not easy to understand and difficult to implement well. Ultimately I see this game with an art reskin and a menu where you can select runes from a pool to actually use ingame and a way to play games to unlock new runes.