its okay, but there's a lot of glitches that make the game annoying and somewhat unplayable. here is a list of what you should look at to make the game a bit more playable and fun.
1. Many of the towers are too under powered as is Link's sword, dealing very low damage to enemies and this becomes a nuisance when the Stronger enemies start showing up. You should add options to power up Links sword and the towers or have new ones unlockable as you progress in the game.
2. The enemies are unbalanced, you start off with weaker ones yes but the knights start showing up in mass droves by the 4th or 5th wave and many of them get passed the towers and link dealing damage before I can kill them.
3. the funds for adding towers is way too scarce, in Tower defense games you usually receive a low amount of funds from every enemy you kill because your actively upgrading and adding towers so a more steady cash flow would be beneficial here, as I have found enemies that drop ruppes few and way to far in between.
4. when i die and retry a level the music is gone, just gone as are the sound effects unless your low on hearts...
5. many of the towers do not seem to deal damage when two or more attack the same enemy, when my army of cucco's attack a knight only the lead one deals damage and the rest don't seem to damage that same knight when they attack it.
6. If link is going to be an active "tower" in the game then his abilities should be upgradeable along with the other towers.
7. many times when you switch weapons the wepon menu stays on screen when it shouldn't