Valkyrie Crusade (jp.:神界のヴァルキリー) is described as a mini-garden and TCG.
The main goal of the game is to collect and evolve different kinds of cards which you use to either fight against other players or go into the campaign mode to conquer different areas and fight against potential archwitches.
Another feature of the game is the ability to build your own city inside your kingdom. You can upgrade important and useful facilities by spending resources on it. Building/Upgrading any facility takes time. In fact, the game is based in real-time, meaning that every minute that passes in real life is a minute passed in the game.
The very first thing a player will do if they enter the world of Valkyrie Crusade is construct their first buildings. There are a lot of either useful ones, or ones that are limited decorations and can be only obtained by via jewels or clearing a special event world.
As explained in the intro, you are also able to upgrade your facilities, like your castle or resource generators and many more. With each level your building is gaining, their upgrade prices and upgrade time increases as well.
The most important base of Valkyrie Crusade are the Cards.
There are hundreds of unique cards that can be obtained by various summoning methods, ranging from the lowest rank (N) to the highest (HUR).
To obtain (N) to (R) ranked cards, you can do a normal summon, which consume 100 friendship points per card.
A more detailed article about summoning can be found here.
Another objective in Valkyrie Crusade is conquering different areas.
The standard world "Celestial Realm" is always available. Some special events offer an additional world during their time.
Conquering areas lets you progress into the game further and also awards you with items after each completed area.
You complete an area by simply conquering all previous areas and the last one (marked as an Castle).
Each area has it's own set of unique "War Trophies". They can be obtained by progressing through the area. The rate of getting one is random, but can be increased by certain facilities like the "Goddess Statue". Special War Trophies are "Sacred Treasures" which can be only found in certain areas. Completing one kind of a sacred treasure allows you to obtain several R Cards.
Throughout your journey, progressing further into the game makes the enemies more difficult. Also, you'll use more vitality to progress, and your progress bar also fills up more and more slowly.
Last but not least but the most important aspect of Valkyrie Crusade is the battle against archwitches. You encounter them randomly but the chance of encountering one can be further increased by special facilities like the "Magic School". Read more about them here.
The campaign does not provide you with complete sets of Sacred Treasures. To collect the remaining ones, you must battle with other players from around the world.
You do not lose a treasure if you lose a battle, and for each battle, win or lose, you have to wait for a specific time to be able to battle again.
Note: When dueling other players, the soldiers lost in battle are permanent, just like in the campaign!
Last but not least, is the Harem system of Valkyrie Crusade what makes the game unique.
The hundreds of individual cards have their own way to express and display their feelings towards their master.
Raising the friendship level of a card to 30 leads into an event where the card usually confesses to the player. The card also gets a 5% bonus to its attack and defense stats.
The friendship level can be raised randomly on any card that you have by 1 level, just by logging into Valkyrie Crusade each day. It also can be leveled up by just having the card in your team when taking part in battles.
Tip: Defeating bosses appears to increase the chances of friendship levels going up, so repeating Campaign 1-1 for 8 vitality each run is a good place to work on maxing friendship.