Hey! Thank you for playing and your comment! Unfortunately this problem with losing focus and being unable to control happens from time to time, I haven't found a solution yet. The final builds will include downloadable versions at least for windows users which won't have this problem. Trying a different browser helps sometimes too.
The goal for this showcase version is to shoot 10 red target blocks by using the bow and arrow mechanic (W key). It seems this was not communicated well enough, sorry for that!