Summary: Fossil Fighters uses a standard turn-based battling format, and combines it with the peak if a child's imaginations, dinosaurs! I started this game at 8, beat it after a year, and came back to it 3 years later, and it is still my favorite game. Its story leaves room for exploration and adds suspense with the digging element. Your goals change throughout the game, from perfecting battle strategy, to collecting vivosaurs.
Summary: the older kid has enjoyed this for a few years, and introduced younger sibling to it. Now younger sibling is very happy to have own copy. If your kid has an interest in dinos/fossils, they will likely enjoy. I have not played it, but sounds like you are challenged to find fossils, fight dinos and can level up and achieve all sorts of dinos. 15yo has done all this, but still plays the game on occasion or is game of choice when playing with younger sib.