Hey its a fun game!
I have some feedback though, i think some varieties in skeletons would be great. For example some skeletons that heal you if you kill them, slow the time or a skeleton that damages nearby skeletons when killed. That would open up more strategic options. Or even boss-skeletons whose words you need to type multiple times.
And also some variety in the spawn of the skeletons, maybe have a little break after you defeated a huge wave because sometimes it felt a bit overwhelming lol. Very nice art style though! Hope it helps