I would consider this a new mechanic, so not during the jam. anyway ;)

Actually I added keyboard primarily for debugging at first, then I added the diagonal directions as well... With some ideas I have for expanding the game concept, I'll likely abandon having multiple trigger buttons anyway.

The timing between the player interactions and the flies is a bit fragile, indeed. Good thing it errs on the players' favour :)

I had some ideas on that or how the base mechanic could be adapted and used in a different game context.

For the jam I just had to settle the scope for a viable core game-loop. And with the progress blockers during the jam (like the weekend event I traveled to), I just managed to get (most of it) in place before the weekend, complete the missing essentials on Friday evening and then had just a bit of time for polishing at the end. I certainly could have used more time for that...

One can always target a field (if not in cooldown) and then try to hit. If you can magically spawn a fly into existence by hitting an empty field, that would be a bug (and not a fly).

Maybe in a future expansion it could be you actually move the frog between fields, so there is no need for an extra cooldown if instead one can only catch a fly if on the same field.