I didn't really play too many disappointing games in 2021, actually. But there is one that comes to mind...
NEO: The World Ends With You (Square Enix, Switch/PS4/PC)
NEO: The World Ends With You very much follows the format of its predecessor, but it doesn't feel as well-polished and fun this time around. While the game certainly looks the part with its pop-art colors and graffiti-inspired style, and even sounds the part with its soundtrack that fuses rock, rap and techno songs to great effect, the gameplay lacks the pop of the original. Combat was chaotic in the original game, but here it's so fast-paced and frantic with the camera constantly shifting and enemies coming at 4-6 fully vulnerable targets at once that it becomes extremely difficult to stay on top of it all, let alone get high marks and gold medals. The puzzles in the original game weren't particularly amazing, but at least had some cleverness to them and told a decent story along the way; here they're drawn out to the point where they completely stop being fun and just feel like the game is actively padding itself out to meet a publisher-mandated length quota. The game even feels more grindy, with even expensive foods barely giving you anything in terms of stats and equipment seeming to barely make a dent in your combat abilities even if you spend the time to grind out the style bonuses. It somehow moves too quickly and too slowly at the same time and, as a result, loses much of the energy the original TWEWY brought to the table. Losing focus on the characters is a big mistake too; throwing in so many, so quickly gives none of them any chance to shine or even develop much personality, which makes the journey much less interesting to follow. A lackluster followup to a great, original game.