OK, where do I start? No fast dropping, which is a bummer. No diagonal matching (which is a game killer, considering that stones arranged next to each other will drop to a diagonal if you match and a remove a stone below one of them, which will happen rather often). Stones matching both horizontal and vertical lines only count for one match, leaving the other matching stones on the board. Combos that are achieved by consecutive matches do not count towards the score. There's probably more ...
Which is all too bad because the game looks rather promising.