making a successful game: 60% well-coordinated TEAMWORK within a knowledgeable group, 30% marketing plus 10% sheer luck. If it is an adventure game, there is also a chance that it will be sought for, even 2 or 3years after its publication, IF you produce something more popular afterwards.
(which will arise interest in your other products)
But if you build the game heavily on visuals (D3D or OpenGL eye-candies),
it will get outdated in less than 2 months; so marketing and timing of publication is quintessential.
I wish you luck with future decisions, too
