Hi! Thanks for playing.
So the combat gameplay is all about typing and when submitting your keys the game will add up attack and armor points. Consonants are worth 1 attack point, and vowels are worth 1 armor.
When typing, the letters will appear below your character, and hitting space/enter will submit the current text. If your texts spells out a word, you will get a multiplier for both values based on the length of the word. This is the core of the combat and dealing big damage.
You can receive new keys from treasure chests, which can be set to active or constant keys by clicking the keyboard in the top-left at the tower. Active keys are the ones that are falling down, and add to your points, where constants can be typed at any time, and aren't worth any points themselves, but they do count towards your word, so are great for forming words easier.
Hope this helps.