This has great style and a great potential for learning, though many kids can solve the levels by treating the game like a puzzle. Kids likely either will make a lot of guesses or reference the hints frequently, as some of the connections to be made among the fossils are tricky. As the level difficulty increases, more connection options are available, including limb structure, teeth type, number of skull holes, body type, ambulatory method, structural type, and more. Some of these connections are easy to spot, such as the difference between an endoskeleton and an exoskeleton, but some are more difficult, such as the ways bone and cartilage are visually represented. Kids likely will need to study the fossils closely to notice small differences, possibly comparing them to real animals they already know about, and to gain understanding.
This game is best played in the context of the learning materials also found on the designer's website, since the game itself doesn't instruct kids on how evolution works or exactly what to look for on the fossils. Plus, since the fossils are fictional, there are general concepts to be learned but not specific information about real prehistoric creatures, which kids often crave. This game is best played within the context of a larger learning experience, including visits to natural history museums, visits to paleontology sites, other instruction about evolution, and/or use of the educational materials on the website. After gaining some context and understanding, kids can dive into this game with an idea of what they're trying to accomplish: drawing evolutionary connections among fossil specimens.