Decent, would be better if the quests (which are the number one source of gems you need to get more mecha) didn't become locked behind a acquire a 3 star part one that takes all the momentum out of it. After spending almost all the gems I had to cycle the parts shop I can say the rare items seem to no drop chance, you can't buy them with money to just clear it, you can't skip it for gems, and so I thinks the 3 stars I can't acquire