Having read your first attempt with Grid Leader, i understand your feeling and the reason you started again from scratch but this time with the soul of the game.
Imho, even if the graphics give the first impression of a remake ("ho, it uses those old graphics, seems to be a good remake !"), as soon as the player starts the game, the real feeling comes up : the soul is all the internal mechanics of the game that are not directly visible to the player, but, when put together, gives the gameplay of the original game, with or without the old gfx.
It seems you did a great job getting those mechanics from your disassembled code and the video reflects this.
The new graphics are slick and the blocky polygons of the car remind me the blocky pixels, i like that.
Keep up the good work and please, keep us informed of any playable alpha release