Really nice game dude! I'm not the best at these so I only made it to wave 19 (where it got really hectic lol). I love the mechanic of only being able to power one at a time, which made me have to think really hard about my placement of turrets. There's a lot of player feedback and the sound effects are awesome!
It might have been worth giving the player a few seconds between waves (showing a countdown) and a hint of what's upcoming so they can plan their buying. A big part is success I guess is switching turrets at the right time and you can get screwed over if placing in the wrong spot or buying wrong (which at frantic times is definitely doable lol).
But great game overall! Really impressed :)
(Btw - The game continues after death. I was tempted to let my electric turret run while I have lunch and pretend my wave score was in the hundreds :P (just kidding lol))