I switched from 3D Gamestudio to Blitz for two main reasons:
flexibility of collision detection (and thus level editing) and skeletal animation. The former means that you can use any arbitrary geometry for your levels (as opposed to needed special maps created in a special level editing tool) while the latter allows all sorts of interesting manipulation of a character (eg. rotate body parts on the fly, place weapons in the character's hand, etc.)
I find programming in 3D using Blitz easier than 2D because so much basic stuff (eg. collision detection, animation playback, etc.) is done for you in 3D.
flexibility of collision detection (and thus level editing) and skeletal animation. The former means that you can use any arbitrary geometry for your levels (as opposed to needed special maps created in a special level editing tool) while the latter allows all sorts of interesting manipulation of a character (eg. rotate body parts on the fly, place weapons in the character's hand, etc.)
I find programming in 3D using Blitz easier than 2D because so much basic stuff (eg. collision detection, animation playback, etc.) is done for you in 3D.