What is the Sky Force: Fighter Combat game, how does it work?

According to the introduction of Ruby Entertainment, Sky Force: Fighter Combat is a Arcade game on the Android platform. There is currently a 1.8.4 version released on Jul 24, 2018, you can see the details below.

Sky Force: Fighter Combat is one of the best Air Combat shooting games that everyone can enjoy! A modern arcade game with intense action and vibrant graphics. Control your fighter through tons of enemies air force in the dogfights.
Fire up your spaceship and starting killing. Now, try to become a Sky Hero of Space, increase your ranking to challenge your friends in the leaderboard.
You can get crystals by fighting against enemy spacecrafts, and use them to upgrade your fighters.
There are 6 spaceships to select, then upgrade it to boost your fire-power to attack enemy aeroplanes.

Game Features:

* Many Spaceships and Weapons to upgrade:
- Military spacecraft equipped a large variety of weapons.
- Lazer spaceship with lazer lock multiple Targets and Dead ray which activates when the ship does not move.
- Flying fighter has the ability discharge at close range.
- Advanced spaceship with sound weapon which has area of effect.
- Ultra spacecraft equipped plasma canon with high fire-power.
- Super phoenix fighter designed compact but extremely solid with high fire-power.

* Procedurally Generated Content:
The procedural content generator can create hundreds of thousands of enemy variations. Combined with the adaptive AI.

* Ranking:
-Shoot'em up with full weapon, get high score and challenge your friends.
-Facebook integration

* Buy items and get free crystal easily:
-Buy item to get power-ups, extra-lives, HP... to be stronger.
-Get crystals to buy items.

DOWNLOAD AND PLAY IT NOW FOR FREE!

What's new in version 1.8.4 -[New] Add bonus free crystal.
-[Update] Reduce app size.
-[Update] Optimize performance.