Actually my brain was not working in that time, because many works was left. So I did not catched the mistake, thanks for letting me know. I will fix it today. The same key for picking and dropping.
The reason for the lag because of browser play.
Electricity, your health decreases if you try to kill any enemy, as its cost. But it regeneration soon if you still stand.
I really want to improve the game, please tell me the part you unsatisfying.
I have given a comment on the health decreases reason.