Just a few words about my upcoming (unnamed) game : it's a shoot them up in the line of DoDonPachi, Under Defeat, in 3d but with 2d gameplay and made with Unity3D.
hi, i've just seen you're message....Since august you may have noticed it : Gamecore3D is dead. And a shameful death since Helios never formalized it.
It seems good, what about the performance? Do you use PoolManager, for exemple, to recycle bullets? And finally, as I also do a shmup under Unity, do you think to share this integretion of bulletML? I thought to use it at first but i had not idea how to do it... Keep going.
Gamecore may handle flight game, at least arcade flight mode, look at MetaJets. A guy from Helios, also work on "space opera" game and i remembered of a demo in the official forum (search at "Arcade flight sim prototype").
GameCore 3D is a DX9 and OpenGL engine. You can choose to export your game for DX9 or OpenGL.
like for every engines, you create your models with a modeler(Blender, Silo, 3ds...) and then import them in the engine.
If you want to learn how to use this engine (faster than by yourself), you can participate to this official online course : 3dgamedesign.co.uk. I do it and it's usefull.
i can't participate to your project (too busy with mine)but good luck.
ingame video : Youtube.com
the answer is yes, the engine can manage large open world.
indie version is available and fully free since few weeks