Molekit

Molekit is a puzzle game built on the real periodic table. Put two H and one O together and you get water. Add C and you're on your way to methane or CO₂. Every molecule in the game is a real one.
 MODES - Endless: atoms keep coming. Build molecules to make room. Watch out for uranium: pair it with two O to make UO₂, or it decays into lead in 6 moves. - Puzzle: handmade closed boxes, no new cards. Use every atom and empty the box. - Reaction Room: 90 seconds. Leftover intermediates like HO fall and bond on their own. Longer chains multiply your points. - Element Duel: a card-and-board battle against the computer. Build molecules to attack and defend. - Molecule Poker and Octet: quick side games about bonds and electrons. ALSO - A new lab box every Monday with tool cards: Undo, Cooler, Pipette, Bunsen, Free atom - Short facts about each molecule you make - Plays in your browser, on phone or desktop Molekit is also coming to iPhone, iPad and Mac. Feedback is welcome in the comments.