We, the pokemon3d.net staff, has from now (2016-09-02) discontinued work on this project and handed it over to a group of volunteers on Github. The project will be open source, and you can help develop it from now on. Check out the repo here.
"Why?" you might ask. We have unfortunatly lost interest in continuing development on Pokémon 3D. Also Nintento of America Inc. sent a DMCA takedown notice to Gamejolt (where this game was hosted) and asked them to remove all games related to Nintendo's work. Read the full DMCA here.
But you can still download the latest version of the game here!
How do I install a GameMode?
If you didn't launch the game in at least version 0.28, do that now. Close the game then.
A new folder called "GameModes" should appear in the \Pokemon\ folder.
Drag the folder with the GameMode.dat file into the GameModes folder.
Now start the game up again.
To play this gamemode, simply start a new game and choose the GameMode you want to play in.