One easy optimization is that if you do not move your mouse when you hit the menu after you complete a level, you can just hit the space button and it will start the next level, which saves time.

The only known exploit currently is Jump Storage, where you have a 2-3 (approx?) frame window to pause after you jump and then resume into another a jump, it will increase your jump height depending on how many times you perform the exploit (you can stack jumps because the frame window is more then one frame, but currently it is most optimal to use it once, creating a jump with double height).

Last tip is that if you feel you are not going to have enough time to shoot blocks coming up, you can pause buffer to give yourself enough time to individually shoot each block.