This is a good game. It's taken some brain power to figure my way around obstacles. It is an excellent tool for anyone seeking to learn the periodic table. (For school or recreation.) However I hit a bit of a snag that didn't seem intentional. On level 11, I had the objective "4 elements with boiling point > 5000 degrees C." Placing the extractors, I realize, only Tantalum (Ta) was registering for the objective. For example Osmium (Os) has a boiling point of 5027C. , and was not being counted. It displayed a boiling point just over 4000C. Oddly enough, when I logged in to mention this, the situation rectified itself. There have been several minor inconsistencies. Aside from this, quite fun. I particularly appreciate the inclusion of idle extraction. I look forward to seeing what else you come up with.