[BrenBarn]

Cool idea and pretty fun. At least for this particular puzzle (island countries) though, I found myself ignoring the feedback and first and just typing as many as I could think of. Then when I did look at the feedback, I mostly just cared about the first letter, not the stuff about number of words.

There are some glitches.

For some reason the size of the grid increased periodically, but I couldn't understand why.

There is inconsistency in the answers. As another commenter mentioned, Ireland was not included. The answers also included both East Timor and Timor-Leste, but these are the same country. Also it seems that Timor-Leste was counted as three words.

Might want to include some kind of ASCII comparison as many people aren't going to type "São Tomé and Príncipe" out.

The hints don't seem to take account of what answers have already been guessed, which makes them useless in many cases. People are probably most likely to ask for a hint when they just have a few left they can't think of; in that case it's kind of crucial that the hint actually be a hint for one of the ones they haven't already gotten.