Not finished. I'll add more a bit later XD I'll write finished in the title once I'm done writing it all.
Okay, so maybe it'd be more accurate to say *almost* 20hrs... it just sounds better than saying 18hrs and 32minutes 
anyway! Here's what I like and don't like about the game thus far, this isn't much of a review as it is more of a second opinion if you were interested in the game. Here we go!
How does the game "feel"?
Whenever I see people talk about this game I often hear it mentioned as a Pokemon-like game. Besides the monster collecting aspect, the game isn't really anything like Pokemon. It very much feels like it's own thing, however some things do feel like call backs to Pokemon such as some of the monster designs, NPC dialogue, and random things like the bikes functioning much like it does in Pokemon. To be honest it plays more like a traditional RPG (in my opinion) than it does a Pokemon game. The setting is primarily urban Japan and it really shows too -which may be a turn off for some people. This game isn't afraid to show where it's from versus the more "universal" appeal of Pokemon, you can tell Level-5 was aiming at a particular demographic with this game. Unlike Pokemon, the game has a heavier emphasis on story and each main quest of the game functions much like an episode of a TV show which I liked a lot. The stories themselves tend to be rather simplistic, however. Overall I like how the game feels and doesn't feel as Pokemon-inspired as I had first thought it might.
Gameplay:
Battles: The gameplay is focused around use of the touchscreen and L and R buttons. Basically your Yo-Kai will auto-attack during the battles and have personalities which determine what the AI will do; for example a Yo-Kai with a more relaxed nature might not attack much during battle while a Yo-Kai with a careful nature might strategize attacks. How the player comes in is through Items, Purification, Targetting, and a button for super moves called a "Soultimate".
Items: Items help you heal, battle, feed your opponent, run away (yes, you have to use an item to run from a battle), and give your Yo-Kai special battle bonuses like a temporary speed increase. Like in Pokemon you can use items to heal your Yo-Kai, this in turn will also help them bond with you more and may even help a Yo-Kai evolve. In battle you may also want to feed your opponent. This benefits you as it increases the likelyhood of a Yo-Kai wanting to befriend you after the fight as this is one of only 4 ways you can obtain Yo-Kai. If you have a food and feed your opponent a food they really like this will greatly increase the chance of a Yo-Kai joining you (however not guaranteed).
Purification: In this game your Yo-Kai can get "inspirited" which can either be a good or bad thing. If you have to purify your Yo-Kai, it'll always be a negative inspirit. Sometimes fellow Yo-Kai on your team may give eachother a speed boost or heal or do something else which is a positive inspirit which is helpful in battle. However enemies can also inspirit your Yo-Kai making them unable to perform a Soultimate move. In order to have your Yo-Kai perform their special move during the course of battle you'll purify them by doing 1 of 3 potential mini games which take like 3 seconds to do. It can add tension during boss fights but most of the time it's just an annoyance.
Targetting: During a battle you can target a Yo-Kai you're battling in order to have a bit more control over who your Yo-Kai are attacking. Also during battles occasionally small glowing orbs will fly on screen, if you target them you may get an item or money. Most of the time I just ignore targetting as the AI is smart enough (usually).
Soultimate: The command you'll use most during battle is the "Soultimate" button which is a super attack that can deal massive damage to an opponent or benefit the front team depending on the type of Yo-Kai you're using. The majority of the time it'll be a powerful attack on enemies. The way this isn't abused is that there is a "soul" meter for each party member. During normal attacks they'll gain more soul for their soul meter in order to allow you to access the soultimate move. This doesn't usually take too long to fill up anyway + the glowing orbs you can target will sometimes give you more soul towards a soultimate move. It's not very strategic but can be fun. My only problem is that these moves are further delayed by very similar mini-games found in the purifying command. They're a bit repetitive and after you've completed the said mini-game it's a further 2-3 seconds delay before they actually perform their super move and in a game like this -those few seconds CAN mean a lot...
Switching out Yo-Kai: You get a party of 6 Yo-Kai you can control over a battle, you use L and R to switch a wheel around to move your Yo-Kai around. It can save one of your critically injured Yo-Kai or help purify an inspirited Yo-Kai if needed. If a Yo-Kai of the same type are battling next to each other they may also get a special bonus. Let's say you have 3 Yo-Kai in the Charm category -they may get a speed boost when they battle together versus 3 different types of Yo-Kai battling with one another.
There are Yo-Kai types! But I wont touch on that T~T
Catching other Yo-Kai: There are 4 ways of obtaining Yo-Kai in the game. Through battle, through a Crank-a-Kai, during a story event, and through evolution/fusion.
Battles: Like previously mentioned you can get a Yo-Kai through battle. After any battle a Yo-Kai may be impressed by your strength and want to become yours. This can be further increased if you feed the Yo-Kai in battle or if you have a Yo-Kai with the Popularity ability. It can be frustrating to get a Yo-Kai you want when the chances of getting the one you want is so random. However I didn't often find it a problem. This reminded me of Dragon Quest V to be honest.
Crank-A-Kai: In the game there is a vending machine which dispenses Yo-Kai. In order to use it you can either find a rare coin or use 10 3DS Play Coins. They can give you special Yo-Kai you cant find anywhere else sometimes. You can only use it 3 times a day.
Story Events: During story events you sometimes obtain a Yo-Kai.
Evolution/Fusion: Like Pokemon if they level up enough they can evolve. They can also be fused together to make more powerful Yo-Kai in specific places.
I'M ADDING MORE HERE LATER!
Things I don't like about Yo-Kai Watch:
-In the game when you run you'll notice there is a stamina meter and it is as annoying as it's used in every game...
-Running from battles. Unless you have an item for running away you CANNOT run from a battle which makes things really annoying from time to time. Thankfully battles don't normally last long but still!
-THE MOTHER FUCKING MAP... Jesus, this thing can be awful sometimes. During certain important missions this thing is useless. Nothing on the map is labled, so unless you look EVERYWHERE in the city, you can get lost for a long time looking for 1 story item. I eventually had to use a guide to find out where to go (this is mainly in reference to upgrading your Yo-Kai Watch to C and B thus far). So if you ever want to upgrade to C and B, just look up the locations for certain criteria because it really isn't worth the time it takes to find certain things.
-The bike/normal running is a bit slow... this is a problem when the map youre exploring is huge.
-Many of the Yo-Kai evolutions/fusions are just color swaps of the original Yo-Kai. Pokemon spoiled me in this regard as *most* of the time the evolution looks at least a little different, but not here. Which makes me think of other RPGs where they just color swap enemies.
How are you enjoying Yo-Kai Watch if you have it?
