Sorry for that.
If you have a decent GPU, try turning on the hardware acceleration in your Chrome/Firefox configuration; it should help to run the graphics part of the game.
Also, check if Chrome/Firefox is allowed to use your graphics card.
The page is not complete. I wasn't expecting someone to play it so soon...
In the last development log, I clarified that Construct 3 has too many limitations when it comes to graphics, so it lags all the time. I, as a developer, can't do much about it at the current state of the game.
Thanks for the shout-out about controllers, I'll leave some explaining in the description.
(If you don't have a good GPU, there's also a trick when you click / (Slash) that allows the low-res downscaling, but the game gets ugly, I'll leave that in the description too)