First off, not a game dev!
This is a cute little Tetris clone, although I'd say the controls are too sensitive (one full keystroke on my Corsair K100 RGB moves the blocks two spaces instead of one), "Credits" is mis-spelled in the menu as "Credis," and the "Exit" button does nothing. I'd also like to see the option to play with more than WASD. Outside of that, this looks lovely!