>>718816658 (OP)
Game A. A good enough story and some good visuals and music can carry an avarage gameplay game a long way (see Bioshock, which is an avarage shooter with oodles of atmosphere and good set design. Don't remember the music, tho). While if only the gameplay is good it's probably a niche game with a high skill requierment to be good at and get invested in; to be seccssesful enough to sell copies, cause the rest of the game will be so dull, so you'll have to ask yourself at some point, why am I even playing this horribly genericly made game? And the only way out if that question is the reward you get from actually managing to play it well (see Dark Souls that had refined, in depth, often tedious to master, combat, but the rest was fine at best. The only reward was beating it despite it's higher then normal difficulty). In summary, you'd get a more fulfilling experience from game A then game B (unless it's a very specific kind of game, and you're into that kind of games to begin with)