This freeware game was published in an unfinished state, and therefor contains a number of glitches and oddities.
Ornitholestes can be heard, but it isn't seen.
In the secret area, if you observe the dinosaurs you've created for long enough, they will start doing impossible things, like walking and disappearing into the mountainside, Allosaurus at times fuse together into a multi-limbed and multi-headed monstrosities, and sometimes they continue attacking the air above dead Diplodocus.
Featured prehistoric animals: Diplodocus, Allosaurus, Stegosaurus and an unidentified pterosaur (based on Rhamphorhynchus' design).
Although sealed off by "invisible walls", the forest can be accessed by tagging the mother Allosaurus, positioning your view the right way, and then un-tagging her. If you are lucky, you will land outside of the game's intended path and can access the sealed-off areas and even climb atop the fallen tree.