Ah, floating point math is „fun”, isn’t it? I had some of these myself, too.
Went straight with Math.round() to get the job done. That was „close enough”.
If you prefer having a game played in Chromium, perhaps add that in the description. Or better: State, that you haven’t tried it elsewhere. That makes it harder for others to assess a game. (Yes, I test mainly in Firefox and consider Chromium an afterthought ^^”)