Not bad
I enjoyed Doodle God a great deal, so that being said obviously I like this game. It is quite annoying, however, that the elements are runestones; the player shouldn't need to clear elements off of the field just because stuff is getting too crowded. Also, why do they act like physical objects? When a combination is successfully made, the runestones bounce off of one another, which kind of sucks if you're trying to keep your field organized. Also, it would be really helpful for the library to list what elements were used to create something, just for reference. I mean, some of it is logical, such as lightning+sand=glass, but for elements such as "void," I have no recollection of how I created that one.
I do like your choice of names for your game... I put quite a bit of time into a game called Ge.Ne.Sis, so I'm a little biased. =)