It's an excellent game, but it's a hit or miss if you like it or not because it has its peculiarities. Also keep in mind that it is not a porn game with RPG and management elements, it's an RPG management game with some porn in it. Portals of Phereon fills a niche, and it fills it masterfully. I've been playing this from way before i found this site, something like version 0.7 maybe (it's come a loooong way over the years).
Now that this is out of the way, review.
Art : as of 0.15.01 the gallery is extensive, with 350+ unique pieces of art on display, and it's really closer to 400 because some gallery entries have multiple artworks. Everything is done in a beautiful hand-painted look, characters look fantastic and have solid designs, without being over-sexualised and out of proportions (some ARE ridiculous but you know and feel it's on purpose, and it's fitting). It's amazing.
Sound design : this game has no audio, but it doesn't feel lacking either. Just pop your favourite playlist in the background.
Gameplay : the learning curve is very, very steep, ye been warned; but it's also very satisfying and well crafted. There is no hand-holding tutorial, but there is an extensive library of information to peruse.
-Many elements of progression interact with each other (RPG exploration, town management and breeding, crafting, quests) and it WILL confuse you at first. But the great thing is that if you feel locked on one avenue of progression, all the others are there to surmount that obstacle. Combining all systems efficiently will skyrocket you into a strong power-fantasy in a short time, and you'll actually feel like a God (story related). Just don't feel bad about losing at first, it gets better and the community will answer your questions helpfully to get you in that sweet spot faster.
-3 heroes with unique abilities and progression that will make you re-think how you play the game and what your short and long term objectives are (besides the main mission). All of them have the ability to snowball their power when done right.
-Unlocks for future runs are done through a mix of in-game discoveries and old-shcool type achievements (some more challenging than others, all doable).
-cheats are available publicly, and will only lock you out of unlocking things (fair enough).
-difficulty customization of the game. It's extensive, and you can really play as easy or hard as you want through the multitude of options.
-Replayability value is to the moon
The porn (is that why you're here?): it's integrated seamlessly into the gameplay, both in the town management and in the RPG exploration. It's the art stills from the characters, some events (both semi-random and active dating), and little animated action bubbles. It's solid enough, and quite wholesome imo, but you should not be afraid of seeing stray dicks or semi/non-human characters.
Story : there's an actual plot, and the author has put some serious effort into creating a believable story and lore. You can absolutely ignore it, but it is there, and you'll be more involved and get a different perspective depending on which hero you choose to play as.