I started to work with CryEngine Sandbox twelve years ago. (damn, already 13 years?) I also work with Game Maker and I'm learning with Unreal Engine 4.
While taking a pause from Syphon Filter mod (there are more reasons for that), I keep working on the Razor Sharp game. Right now I'm making a simple tool for modeling cars for the game.
For many reasons I've restarted the development. Now I'm making the game in a fully 3d environment, not just a fake 2d.
For slower computers, there will be an option to switch between 3d models and 2d sprites of vehicles.
oh, i hope you will finish it :) will you now do a real GTA2 engine?
a second question: you really write a own tool for modeling your objects ?!? (yawdropping...)
Well, not really.
The tool is a "game" where you can change coordinates of the few polygons the car have and then export them as .txt, so the game itself can load it as an external model. People have made much better tools but this is enough for it's purpose.
I don't think I'm making an engine. I'm just making a game using Game Maker, so I have to write things like behavior of cars etc.