Hyrule Warriors: Age of Imprisonment boasts one of the best combat systems to ever grace a Warriors game, and its story does a fantastic job setting up the events of Tears of the Kingdom. Unfortunately, however, the overall experience is dragged down by the utterly abysmal implementation of side content and some baffling design choices that serve only to waste the player's time.
The main campaign is highly enjoyable, but to keep up with the recommended levels, players will need to engage with quite a few of the side missions. There are at least 148 of these (I'm assuming there are two more, but I've given up trying to unlock them for the time being), pretty much all of which follow the exact same formula: explore a small portion of one of the story mode maps and defeat boss enemies until a large boss enemy shows up (usually a Lynel). Needless to say, this quickly gets old.
Completing certain side missions will liberate parts of Hyrule, not long after which, players will need to defend the territory again from enemy forces. They'll only have a set amount of time to do so (usually four battles), which can be frustrating when all you want to do is dive back into the main story. Most side missions can be completed in two or three minutes, although that's not always a good thing.
Some side missions require players to use specific characters, but these characters are then selected as the player's default choices when they head into subsequent missions, forcing them to delve back into the menu and reselect their preferred team each time. Combine this with loading times, selecting camp supplies, and navigating through results screens, and players will soon find that they're spending more time preparing for battles than actually fighting them.
Side content is supposed to be optional, but when new characters and stat increases are locked away behind it, it feels like a requirement, and when it's this bad, it brings the rest of the game down with it.