The first time I tried to play this game, it took me 4 hours to realize that it was going to be a long, long, long game without too much action front-loaded into it. It felt really weird and corny, and I wasn't willing to spend the time to get into it or get invested into the characters.
The second time I tried to play this game, it took me 10 hours before I realized how special this game is. I got sucked into the world, the characters, the day-to-day things you do to chill or "better yourself" (game-wise, at least). The concept behind the game ("phantom thieves") is weirdly original, and I was all for it by the time I got to the 2nd or 3rd dungeon. By the end of the game I was playing the "world will change" theme on repeat since I was so into it.
I will also so that the gameplay is really, really fun for an RPG! I hate random encounters, I hate turn-based battles. But P5 gives the player the option to battle enemies, or even ambush them for a significant upper hand in battle. I felt like this stealth mechanic actually drew me into more random encounters because I love sneaking around. Besides that, the battles themselves are super high energy and animated, and really fun to play, even if it's a turn-based battle. The battle soundtracks (normal, mini-boss, and boss) are just absolute bangers for video game music. I always felt super bad-ass going into a difficult fight.
The dating sim component of this game was also really fun. I've never, ever played a dating sim before but having the characters be so likable really made it a part of the game I didn't expect to enjoy.
For things I didn't like, I will say that it is a significant investment to play, and you'd need at least 10-20 hours of gameplay before you start getting absolutely hooked. And even after that, it takes another 60-80 hours to finish the game... and this is just for P5 vanilla, not Royal. I will also say some boss battles feel gimmicky / too easy to me, and I don't like you can get an immediate game over if Joker dies (even if the other party members are still alive). I also don't like how you have to leave a dungeon to reload bullets - this actually made me want to use guns less in battle, unless I knew they were going to be crits on the enemy. (This is my first Atlus game, so maybe that's just the mechanics of the series that I just need to get used to.)
I'm normally not into JRPGs, but this game is just something else. I was super sad when the game was over (I really didn't want it to end), and there are very, very few games where I actually felt this way. So kudos, P5, for making me feel something so deep and special, in a way not many other games can.
(I'm rating this 4/5 instead of 5/5 because I'm going to play P5R once some time passes, and I'm expecting that the QOL improvements in that game + the additional content will bump the rating of that game up to a 5, but we'll see after I actually play it.)