imo they put huge-huge amount of professional 3d art into the game, concentrating on all details: models, animations, background, menus, cutscenes, sounds, talks, effects, textures etc. the levels are very different, so each of them requires long design time, not just reorganization of a similar environment to get a new one. it includes a couple of game play type, so probably it's fun to play. I really don't know why they don't make an english version...