this is weird, i'm guessing moving and jumping works since you were able to get to the first letter, but are you able to interact with the board next to the letter? (it's supposed to be the same button as picking up the letter)
and does it work with the keyboard? (cause if not then the problem is not about the controller)
also, what browser are you using? and what controller type? (sorry about all the questions but it helps me to understand where the problem may be coming from, as i have absolutely no idea)
if you can, you could also download the game to see if it works better than in the browser (if the download doesn't work, read the instructions below the download button because there are problems with some browsers)
i'm very sorry about this i'll see what i can do, i hope you'll be able to play it, and thanks for the kind words!