Wrong difficulty and poor option selections
Let me get one thing out of the way, the graphics are just fine, I love them to be honest.
By difficult and challenging, you forgot to explain what kind. The difficulty is fake difficulty, the block-tutorial itself is impossible to pass by because when you press spacebar for the second block, you will pull it back. But if you let go of either button, no order or holding, your character walks into the block and it is completely impossible to actually complete the level.
Second is options, do NOT make you hold a button to actually do something. When I first tried to restart on said block level, I thought I was stuck and could no restart. Then I learned you have to hold it, but there is no way you can know otherwise. Also, make "Q" a button to change quality, not to quit. This is because most computers may have poor connection and the game may slow down, you'd want to lower the quality to have a fighting chance of actually -you know- PLAYING. Make a button for quitting "Escape" or "Esc." Just because you can use alliteration for buttons does not mean you should. The rule only works with restart, mute, and pause; other than that: DO NOT DO IT.
The music and sound-effects themselves are poor and loop a lot, which gives me a bit of a headache as even though I cannot stand no sound at all, I hate looping sounds even more.
Please adjust the block glitch, change buttons for quit, and add an ability to toggle the quality, please. Either that or just delete this submission altogether as it insults Shift and the rest of it's games.