Since this is most likely supposed to be a kids game I can't really say all to much to its complexity. It is a bit unfair for kids though, since there is a timer and also some very Waldo-like differences. That makes it more interesting for non-kids but why would they play a spot the difference anyway? The soundtrack is ok but gets annoying over time, but it can be muted. The game has the big plusside, that differences can be clicked on both screens. The main reason why the rating isn't all that high is first, that you don't see what exactly the final difference is with each dinosaur and second, that there is no punishment for wildly clicking around on the pictures and "finding" differences in the process.