I been doing 3d interactive for almost 7 years now and yes, its been really hard to create one. You have to do 3d modeling, rigging, animation, export to compliant format properly, then the hardest thing of all – the coding to make it interactive or a game, then compile for web or offline based application.
In just 1-2 weeks i have deployed a simple multi-player 3d game. Yes, its not yet done, but the functionality is almost done. Building a network application really takes heck of time and efforts but with unity3d i can say that “i finally found the one” hehe. Back then it takes months for the same thing/output.
Well, please try my unfinished but working multiplayer 3d game created using unity3d.
Instruction, download and play – see “network.exe” run it – click start server, copy the zipped file to another computer with the same network, then type-in the IP address (replace the 192.168.10.1 with the server’s IP address) – then voila – you will see each other’s player (a box that will move & shoot using WASD & Space keys). By the way there will be lots of gray cube (enemies with programmed Artificial Intelligence & rigidbody/physics) that will chase your player – enemies can be shoot but wont die for now hehehe