Star Force

Star Force is a vertical shooter developed by Tecmo (known at the time as Tehkan). It was released in some arcades outside of Japan as Mega Force. The game consists of a single fighter ship flying through space, and occasionally over floating terrain while being attacked by enemy ships, and destroying land based targets. The only weapon is the ship's guns, but they can be enhanced through a single power up that attaches to the ship and grants the player rapid fire capability.

Received considerably better in Japan than it was in the U.S., Star Force is considered repetitive by many American players, while others applaud the game for its degree of challenge. It was converted to several popular Japanese systems such as the Famicom, MSX, Sega SG-1000, and the Sharp X68000 home computer, as well as a Mobile phone app. The only system to ever see an American release was the NES, where the game was actually improved over the original Japanese release. Star Force was remade in 1995, along with two other NES shooters with very little upgraded, for the SNES in the Japan only release of the Caravan Shooting Collection. It was also included in Hudson's compilation of Famicom shooters in 2006 in Hudson Best Collection Vol. 5.

Story
In the year 2010 of Dimension Almanac, there was a mysterious planet named GORDESS which was moving in the darkness of the cosmos for the purpose of mass murder and plunder. Everyone gave up fighting against GORDESS because of its awesome power. One day a brave soldier riding a space patroller challenged GORDESS to fight. People called this space patroller "FINAL STAR", wishing to be saved. You must bring an end to the murders which have been committed for the past 2,000 years.

Controls

 * Joystick: Use the joystick to move the ship in any one of eight directions. The ship is capable of moving to any location on the visible screen.
 * Fire: Press Fire to shoot twin bullets in an upward direction. If you collect the power-up known as the purser, you can hold the Fire button down for rapid fire.
 * 1-2 Players: Press to start a one or two player game.

Gameplay
The player must pilot a spaceship over series series of islands - drifting in outer-space - shooting enemy spacecraft and ground-based targets. Special symbols appear at regular intervals and can be shot or collected for bonuses. The levels are designated by letters of the Greek alphabet.

A single power-up, known as a purser, must first be shot before it can be collected. It first appears as a brown circle. Contact with this circle will destroy your ship. Once it is shot, the purser appears in the form of a smaller ship, which can be collected in order to grant your ship rapid fire power. Most of the time, this power-up shows up right after mid-boss.

There are 25 levels and each is marked with a letter. The first 24 letters pertain the to greek alphabet (Alpha, Beta, Gamma, Delta, etc.) The final level is marked with letter "I" for "Infinity". After beating 25th level, it will just repeat itself.

The order of the stages are as follows: A B G D E Z E T I K L M N X O P R S T U P C P O I

Enemies in the game have predetermined patterns of appearance, as well as stage backgrounds. That means after some time they just repeat themselves (except bosses which are unique to a stage, although very similar).

Each level has an end-of-level boss that must be defeated before the player can progress to the next level. The boss itself has no offensive abilities other than collision, however the platform that it launches from contains two cannons that fire a few shots at your ship before scrolling off the screen.

Tips & Tricks

 * You can determine which direction the end of level boss will move before it even appears by looking at your score. If the hundreds digit is odd, the boss will move to the left. If it is even, it'll move right (the tens and units digits are always zero).
 * 1,000,000 Points Bonus : On the violet continent, if you see a coelacanth fossil on the left side, go to the right side and shoot. Cleopatra appears - shoot her and you'll get a million-point bonus. The coelacanth may only appear on the third violet continent.
 * 80,000 Points Bonus : At some points in the game you will see two columns of green arrows down the center of the screen. Concentrate on either the left or right column of these arrows, and try to shoot 10 in a row. You will be awarded an 80,000-point bonus for doing this. The first time these appear, it is possible to get more than 3 such bonuses in a row, and sometimes more if the level ends before the column has finished appearing. Later on there is a short two-column of only 16, and you can get 2 bonuses in a row here.
 * 50,000 Points Bonus : There is a stage mid-boss that combines into parts. When you hear the tune indicating that it is about to appear, stop shooting (You don't actually have to stop shooting altogether, but if you hit part of the enemy before the center part flashes white the bonus will not work). Position your ship so that you are just underneath the center part of the enemy and wait for it to flash white. Once this has happened, shoot the center part several times : the enemy will be destroyed and you will be awarded the 50,000 point special bonus.
 * In later stages, there is an enemy that appears behind you, so you cannot react to it as you do to other enemies since you will mostly be near bottom of screen. This enemy's appearance can be predicted. Whenever there's about 2 second delay for enemy's appearance in later stages, you can expect that this enemy will come behind you at which point you should go far left and avoid bullets by moving vertically.
 * There are 3 types of enemies that you can use to beat any stage more easily. This trick only works in Japanese version, although you can still use this trick in USA and EU version of the game to stall enemy appearance and shoot some objects. The enemies are:
 * The enemy which assembles from 4 different directions into one bigger enemy.
 * The enemies which explode when you shoot them, creating 4 projectiles.
 * The rotating enemies shaped like cube.
 * When you see these enemies, don't kill them. Avoid them so that they chase you while you shoot as many objects as you can until you reach boss. You must shoot objects in order to trigger the appearance of the boss.  It will only show up after enough enemies or objects are destroyed.
 * When dealing with enemy type #2, try to line them up by going into any corner and wait for them to follow you. That way they occupy the same location and take less space on screen so you can move more freely.
 * In USA and EU version of the game, enemy type #1 will not chase you, he just disappears off screen. Enemy type #2 will chase you at which point you can avoid it for a while until it eventually speeds up and catches you, at which point you can kill it by shooting when it's next to you on your right or left side. Enemy #3 also speeds up and catches up with you eventually, so kill it before it gets too fast.

Home Conversions
The Famicom, Sega SG-1000, and MSX conversions are close replications of the arcade game, but as expected, the 16-bit Sharp X68000 boasts a near perfect translation of the arcade game (the X68000 was particularly famous for the accuracy of its arcade translations.)

The NES conversion of Star Force contained a few graphical and gameplay improvements over the Famicom version that improved the accuracy of the port. The enemies are harder. Enemies and objects are colored differently. Sounds were changed slightly, although the songs remained the same. The Game Over theme is a new addition to NES version. The title screen was altered. The question mark tiles have different icon after being shot which are on the right side instead of the left.

Star Force was also converted for play on mobile phones.