9) Watch Dogs
Talk about an E3 trailer that promised the world. Watch Dogs stole the show at E3 2012 with a spectacular showing that introduced a sandbox that truly was your playground. Two years later, the full game came out and it was a shadow of its former self.
So, what happened? One theory is that Ubisoft overestimated the power of current-gen consoles and went hell for leather with their E3 demo. It looked fantastic, with beautiful environmental effects, realistic lighting and bokeh depth of field (a technique that renders objects in the background out of focus).
The final product, however, was nowhere near that level of graphical fidelity. Lighting was flat, the environmental effects were pared back and bokeh was entirely missing. Worse still, the game was derivative and dull.
Color us disappointed.