Yeah ! that's right !

But perhaps you can mix 2D and 3D also with 3DGS, like you said 3DGS is not
oriented to this style of game and the other tool is fully dedicaced to
adventure games.
But your game will not be full 3D ,but mix of 2D,3D ?
And 3D in this tool i think is not as advanced as with pixel shaders and some
amazing effects that would be prerended in 2D (particle effects, bump mapping!!
well perhaps try it and see what gives the best results.