Shadow the Hedgehog

Shadow the Hedgehog is one of the most controversial experiments in the history of the Sonic series. Sega Studio USA decided to build a standalone game around the blue hedgehog's dark counterpart while also trying to appeal to older players who had grown up with the series – Shadow thus wields weapons, rides motorcycles and vehicles, and instead of jumping over rings, at times shoots at enemy soldiers and alien creatures, giving the game a noticeably more action-oriented and gritty tone than the series' classic platforming entries.

The central storyline revolves around Shadow's memory loss and search for his own identity: he does not know whether he is a clone or a real being, and he does not know whom he can actually trust or which side of the coming conflict he should actually stand on. The game carries this uncertainty directly into the gameplay through a system of moral choices – at the end of most levels, the player chooses between a heroic, dark, or neutral path, which branches the story into dozens of different combinations of missions and endings. This approach was unusually ambitious for its time, as it forced players to go through the game repeatedly to uncover all the possible branches, even though it was not always fully polished and some paths felt more similar to each other than a player might expect.

Critics at the time were sharpest on the weapons and the dark tone, which felt like an excessive, forced attempt to appeal to an older audience in contrast to the series' established tone, and reviews were accordingly mixed to negative. Nevertheless, thanks to its over-the-top nature, huge number of endings, and the unforgettable character of the alien overlord Black Doom and his race, the Black Arms, Shadow the Hedgehog has built up a strong cult following over the years, one that still remembers it today, with a fair dose of nostalgia and irony, as one of the strangest yet also most interesting side trips in the entire Sonic brand.