I'm glad you were able to play it and that you enjoyed it :)
Is it possible to find out which browser you're using? Because I can't reproduce the problem you're talking about.
Here. Important to mention that the HUD keyboard doesnt show my arrow keys, but I am pressing them as well. I would also like to mention that when the in-game cursor moves, that's not me moving it. You can see that it's not me when I get out of full screen and move it outside the window while the in-game cursor is still in the same place. When the guy moves, that's not me either. I only press any keys after/before, so he just kinda moved on his own.
Okay, I think I understand what's going on. There is a lot of lag on many things in the game (including the cursor which is a custom cursor).
This is certainly caused by the numerous effects (particles, multiple interpolations on each brick and on each leaf, several CRT and Glitch filters, etc) which require a lot of CPU and graphics card resources.
If I were to make a more complete version of the game, I'd certainly add a menu to activate/deactivate these options, as well as a message warning of possible lag. In the meantime, you can always try unchecking the “Filter” box at the bottom left of the screen. I don't know if this will be enough, but it should certainly cost less resources.
Thanks for taking the time to make this video and for telling me about the problem :)