Do you like ARPG, awesome story and don't mind anime style? Well, then this is what you have been searching for your whole life.
As you start the game, you can select between playing Hugo and Yunica. Hugo is like an SMG, you can spam your basic attacks like crazy, but is slower than a slowpoke. And Yunica has oven mittens... oh, and an axe, and is quite mobile. After that you can choose your difficulty, whereas nightmare really is a nightmare, and easy for Hugo players (yes, I hate him and I can't play him).
In this game, nightmare actually adds stuffs like attacks to the enemies, not just way more health and damage. Don't worry if you get stuck on a boss for 3+ hours in this mode.
Upgrading your character is also possible. You get small crystals which are your ingame-coins. In Nightmare every crystal is 1 point worth. In every other difficulty, I think, the bigger crystals give way more points.
The goddesses are nowwhere to be found on Ys. It's your job to go to the surface and find them. Of course, they are in the giant Darm Tower, the lair of the evil guys. Depending on which character you play, the story changes a bit. You get a few different bosses and other cutscenes. Due to this, you want to play it again, just to see how everything plays out for each character.
Overall, to leave it mostly spoilerfree: Each story had it's emotional part and was well thought-out.
Hugo: Will make your hands hurt (You should map a key to autopress the shoot button 30x a second)
Yunica: Solid Movement, good attack speed, fun to play and mittens.
There are a lot of enemies. Some are just powered up versions of older enemies, others are completely new. Especially on Nightmare difficulty you have to be very carefully to choose how to deal with the enemy. Some are almost completely immun to your skills. Learing the patterns of your foes helps a great deal.
You play in a huge tower. However, this doesn't mean the interior is all the same. Every time after one of the bigger bosses, the tower changes completely. One time you play with lava, the other time you play with sand and also mirrors!
Yes, this game has unlockables. Once you complete the game with any character, you unlock something awesome and the boss rush mode. After you finish the game with every character, you get the arena mode and a shop. In the first you defeat enemies for points, which then can be exchanged for stuff in the latter one. The shop allows you to buy many things, like powered up spells, Hugo still sucks though.
Just listen to the trailer music. It's so awesome! The rest is also pretty good.
Long story short:
Buy it, so we get even more Ys on steam!