For me, I would make a list of games that I *did* complete. I always find myself immensely reluctant to continue playing game once I have explored most of the mechanics. Then the only real encouragement remaining is a good story. Most games offer a limp wet noodle of a progression in that department after half their lengths. This is bad because after becoming a physical deity in the game, the real motivation to keep on going is the mystery of what is to come. Once that is reduced to "Go and defeat the ancient dragon/ demon/ god/ his cultists", there is no drive in the game except the mindless desire to see it to the end. One would think that since such a situation is almost ubiquitous in most games under the category of RPGs, someone would figure out sooner or later that the progression of the story has to correspond to the mechanics progression thus offering a changing gameplay throughout the length of the game. But it seems that till date most games have missed such an opportunity to come up with a product that engages us from beginning to the end.
For example, I loved the new Blackguards game in terms of its Turn based gameplay. But after I had leveled all my party to the utmost skill levels, I did not find myself motivated enough to play ahead. This particular experience has held true for me almost for all the RPGs I have played. Dragon age, NWN, NWN2, IWDs, Wizardry, Summoner, Diablo, Gothics, TOEE etc I just could not bring myself to finish.
It is quite an exercise for myself, when I consider what games I finished. Torment, for example, had a mediocre mechanics, but the story alone allowed me to pull the dead weight of the game to the end. Same holds true for Deus Ex and the second vampires game. These games had some interesting gameplay elements, but they fizzled out halfway through.
So overall I feel that mechanics alone can not carry a game. You need a good story to take it to the end.
