In case you didn't know already, Hyrule Warriors is a crossover between The Legend of Zelda and Dynasty Warriors with the latter's gameplay being used as the framework in which the Nintendo universe was injected. As such, this game doesn't play and feel like a usual Zelda adventure, but that's not necessarily a bad thing.
You are forced to start with story mode, although you are allowed to do something else right after the first level has been completed. The introduction to Warriors gameplay feels overwhelming with messages constantly popping up, flashing map icons and the actual enemies in front of you. This takes a good while to get used to and it's necessary to stand a chance in more difficult stages. Thankfully the pause menu gives you access to a lot of information, so you can look up the exact positions of important allies and enemies while taking a break from the action. Hyrule Warriors is not just about mindlessly killing foes, it also features a good dose of strategy. Certain enemies should be killed as fast as possible, fortresses should be seized to steal the opponent's respawn points and make it your own while these fortresses at the same time can serve as roadblocks for the enemy's forces on their way to your headquarters, and at some point you might want to explore the map a bit to find one or the other goodie.
The game pits you against dozens of enemies at once, but the vast majority of them are harmless and rarely launch an attack. Their only purposes are to convey the sense of a huge battle going on and to rack up a high kill count. They can and should be ignored for the most part (the exception is inside fortresses). Your focus should be on the higher ups, especially because they spawn minions as long as they are alive. Fighting is usually done by repeatedly pressing the normal attack button with a strong attack added at the end. The lock-on function from the 3D Zelda games is present and helps a lot to not lose focus on what you are supposed to kill, although at times it disconnects for no apparent reason or doesn't want you to switch to another enemy or your desired enemy with the right stick. Every now and then you can launch a special attack once a bar has been filled. Even rarer is the use of magic which is another separate bar that allows you to go into rampage mode where all of your attacks become unblockable.
The rewards for all that hacking and slashing are many. Firstly, there is a basic level up system; your attack power increases with each level up while you get an additional heart container at each level that ends with a 5. Secondly, enemies drop materials that are used for upgrades; there are plenty of ways to make your characters stronger. Thirdly, enemies can also drop weapons on occasion. Lastly, there are rupees which are spent on upgrades in conjunction with the aforementioned materials, but they can also be used to buy EXP; the cap is equal to the level of your best character. Intelligent game design becomes apparent when you realize that unneeded material can be used to create potions that increase the probability of good and rare weapon drops; unneeded weapons can be sold off and that money in turn can buy you level ups for weak characters or some you just don't like to play as, but are forced to use every now and then. So in the end nothing you find along the way has go to waste and that keeps the motivation high. Another plus point is that failure on a mission alllows you to keep the EXP you gathered, so it doesn't happen that you spend 20 minutes and having nothing to show for it.
Story mode does its best to string the universes of Ocarina of Time, Twilight Princess and Skyward Sword together while introducting new friends and villains. It's a campaign that lasts anywhere between eight to ten hours and allows free character selection in free play mode, but the real meat is to be found in adventure mode. Each of the 128 tiles of the original The Legend of Zelda overworld contains a mission and various prizes, including one-time use item cards. Moving on to further tiles requires certain ranks (A, B, C) while some of the rewards have to be unlocked by first using an item card on the map and then completing the mission in question. Additional heart pieces and containers for the 13 playable characters are nice, but the real deal are the new and stronger weapons you can unlock. The missions come in the form of story mode-like objectives (around 15-20 minutes long) as well as various simpler tasks that can be completed in 5-10 minutes (kill all enemies, kill the right enemies, kill a couple of big monsters, kill a certain number of enemies etc.). All in all, adventure mode should last anywhere between 20 to 30 hours until you reach the end of it, plus a good amount of additional playtime to get all rewards and A ranks.
All game modes can be played in offline co-op, one player using the Gamepad, the other the TV screen. The enemy count is reduced, but this only goes for the cannon fodder that wouldn't pose a challenge anyway. The thing that is an actual issue is the framerate. While in singleplayer there is only the occasional slowdown that still leaves the game in a playable state, that is a much more regular occurence in co-op. But what's worse, on the busier maps the action can slow to a crawl which kills the mood a bit; things get notably better once a few of the important enemies have been killed. Another problem are the controller options: Wii Classic Controllers are not supported at all for some inexplicable reason while the Wiimote+Nunchuk combo forces the normal attack on motion control; odd, because the game allows the freedom to freely assign some of the other buttons; Wiimote-swinging should have been saved for executing a special attack; in case you wonder, the Wii U Pro Controller is as customizable as the Gamepad, so there is at least one definitely viable option. Despite those issues, co-op is still a lot of fun because it allows you to cope with the constantly incoming new objectives and enemy hordes much better than when you are alone.
Whereas the graphics don't live up to the standards that can be expected, the music certainly does. The remixes of epic Zelda compositions are simply great and don't get repetitive like the gameplay tends to. Performing the same combos over and over again gets tiresome at some point, although it definitely helps that the 13 characters all play distinctly different. More bosses from Zelda games being used as big monsters would have been welcome too; there are only five, so I felt reminded of Monster Hunter Tri where you killed the same thing over and over again with the same few combos. Thankfully, Hyrule Warriors also puts you up against all playable characters as bosses, plus it doesn't take ages to kill them, so the game never hits the lows of Capcom's incredibly monotonous and insanely padded hunting game.
Final Score: 7.3/10
Hyrule Warriors works for the most part. There are some control and technical issues, but they don't get too much in the way of the fun. It's a game that keeps you hooked for a while, because the rewards are plentiful and the next level up or upgrade is never far away. However, maxing out all of your characters will be a slow and long process, and that's where the motivation to continue playing takes a nosedive. If you like Zelda, this is still a definite buy though, because by the point where things get rough you will have already gotten your money's worth.