Exploring crossed with typing is an interesting combination! I made a typing themed game last Kenney Jam, so it was cool to see one this jam as well!
I do think that word mode is easier to play than random letter mode. I had to think a lot more about where the letters were on the keyboard for sequences like "sjf" and "fld" and "kjs" than the word equivalent. So I could definitely recommend just switching to words instead!
I'm sure you could expand the gameplay further by having to type words over enemies to attack them with fireball spells or something of that sort :)