So after finding the first three letters (MOP) am I supposed to be able to do anything by inputting those and pressing space? I can't seem to input more than 2 letters.
In theory yes; but there are some keyboards that can't recognize too many key presses at once, so that may be what is happening? But, if you were able to pass the "enter play" section, I guess that can't be it? I recommend trying to press them all together or one by one (without releasing any of them) and then pressing space.
Sorry for the inconvenience! :'(