Nice game! A couple points of feedback, maybe limit how many turrets you can place. You can just fill the whole screen with turrets and it just goes forever. Maybe add a UI for your lives so it just doesn't end all of a sudden. Also, I don't know how I did it, but the first time I played it the enemies started glitching out and went all over my screen. Overall, the game looks good, you got the basics in.
I also did a tower defense theme game if you wanna check it out and give feed back, thanks