Yeah i guess the atom building is still kinda not too obvious especially for people with absolutely zero chemistry knowledge :p the only thing in the game is the possible bonds list on the left of the screen that shows if your selected atoms can bond and with what, so i guess it kinda like rewards the player since as you play on youll start learning what atoms are at which number like 8 being oxygen. But anyways yeah guess thats the more "find out"y part of the game lol