Ok finally gotten the game to work on Firefox instead. Its a cool and fresh game for sure so you did nail the main concepts workings of your game and I think there are some places where this game can improve.
- You could specify which arrow to click in the first part of the tutorial (the bottom part of the game view also had an arrow so I kept clicking that) or just change the symbol to circle or something.
- Give the option to remove the turret or imps placed in the kingdom. I accidentally placed some turrets in places I didn't want it and that caused me to lose a bunch of times.
- You could also randomize at which horizontal lane the wave will arrive instead of having them come at the same place again and again when you repeat the game but I think its fine for this game just a point to think off in your next game.
- Add some animations. Since your using 8bit artwork it shouldn't be hard to add some animations in them. Animations makes your game feel alive and without them it feels a bit dead no matter how much features you add.
Try out Balmung its a great 8 bit game and one of the best tic-80 games and should give you better idea on how to improve your game. I don't know why its not popular despite it being fully functional Zelda like game.