You are oxygen: let 2 hydrogens through and block the rest. The shield can break; if an enemy touches you, you lose.
Loading 3D scene…
Loading 3D scene…
Your privacy on this site
We use cookies and local storage only with your permission. Essential ones keep the site working; analytics help us understand usage via Google Analytics. You can reject all optional data. Read more in the Privacy policy
Privacy preferences
Essential
Language preference, cookie choice, and basic site operation. These cannot be turned off.
Always on
Analytics
Google Analytics (anonymous visit and page metrics). If off, we do not load that service or use geolocation to suggest language.