well, actually this is the worst place to ask something like that. Everyone will tell you it is a perfect fascinating incridible game and that you have to play it....
Better here the reviewers
Grim Fandango is an adventure game(plot riddles, character talks etc), same as the previous adventures mama Lucasarts has made. It does use a new engine thus making the control thoughout the keyboard and not the mouse.
the story is taking place in the land of the dead...(and better check the review