Space Battle

Space Battle is an Asteroids-style game. It is the first Windows remake of Atari's arcade game Space Duel on the internet. The game contains sprites flashing in bright colours against a black background.

Later in June 2018, the Atari 2600 version of Space Battle was released, with some gameplay improvements.

Origins
After learning about how vector graphics truly look in real life (they glow, flicker, and leave an afterimage) and seeing a vector game remake exhibiting some of these characteristics, Tangent decided to create a vector game exhibiting them as well. The first attempt was Galactic Fortress, the first of Tangent's standalone vector game (the first vector game being the Undyne minigame from Len'entale). Galactic Fortress was in monochrome, which is why "colour fading" didn't occur there. Tangent was not expecting the colour to fade when transitioning the pictures from PowerPoint onto Game Maker, but there was not really any helping it. It does perhaps, however, give it some sort of realistic look.

Later, Tangent drew a picture of glowing vectors depicting Atari's arcade game Space Duel, a game in the Asteroids series. Some time later, they decided to create a game out of it, and used the existing old game Game Maker Defender they made during the Vista era (see: Post-Vista era), itself an offspring of the Space Cleaner Game Maker tutorial, as the base game. Due to the ease of not having to do everything from scratch, this finally sparked Tangent's motivation into making a game they were content with again after the game depression period from the start of the Post-Vista era when they had little motivation to perfect games.

The original plan was to have only 5 levels, followed by a boss battle (similar to its predecessor), but after playtesting, Tangent found that they really liked the game and wanted to continue playing past 5 levels, so they scrapped the boss idea and made the game endless, and added an Intermediate difficulty mode to make things easier and thus allow the player to more easily get further into the game.

Object and gameplay
The object of the game is to reach a high level. There was originally a scoring system planned, but it was ultimately not included, partially due to Tangent still recovering from the game depression and partially due to exploits where a player could get an infinite number of points just by waiting for UFOs to come without progressing through levels.

The player levels up by controller their spaceship(s) and shooting at, thereby eventually getting rid of, all the space objects (except mines) on the screen. Most objects wrap around the screen (i.e. exit one side and come out the other). The game ends when the player loses all their lives.

Controls
The player may turn clockwise and counter-clockwise with the left and right arrow keys. Up thrusts and X fires.

Z and down performs the power-up action (aside from retro-thrusting, i.e. hyperspace, flip, or shield) and retro-thrusts respectively. These buttons only function after corresponding power-ups have been picked up.

Power-ups
If a player shoots a red or green flying saucer, a power-up appears. There are 4 power-ups (+ Mystery) which may be picked up, 3 of which are based on the Atari 2600 port of Asteroids, the remaining of which is based on an online Asteroids remake. The newest power-up the player picks up replaces any previous ones. Power-ups are retained even after losing a life.
 * Hyperspace: Your ship disappears momentarily and respawns at any location, which could even be outside of the screen. Should be used sparingly, as it is more dangerous the more objects there are on the screen at the time.
 * Flip: Instantly flips your ship 180 degrees.
 * Shield: Hold down Z to make your ship(s) invulnerable for as long as you hold down the button, up to 1.5 seconds. If after 1.5 seconds, the button is still not released, the ships explode. No object rebounds off of the shields - it will simply pass through the player's ships unharmed.
 * Retros: Activates retro-thrusting. Allows your ship to move backwards. Retro-thrusting is slower than forward thrusting.
 * Mystery: Selects one of the above 4 power-ups at random. Pressing Z (or down) to test what power-up was earned is recommended when the screen is reasonably clear of objects.

Enemies and dangers
Main article: Space Duel - Strategy Wiki
 * Space objects: The most abundant and regular danger you will encounter in the game. These objects replace the asteroids from Asteroids and travel diagonally. Shooting a large object splits it into 2 medium-sized objects. Shooting one of those splits it into 2 small objects, and shooting a small object destroys it. The smaller an object's size, the faster it travels. Get rid of all of them, as well as all other destructible dangers on the screen, to progress to the next level.
 * Space mines: Small plus-sign-looking objects that travel around the screen in a random direction. When shot, a mine freezes momentarily and changes its colour, before resuming back in the direction it headed in at a higher speed. If a mine turns white, one more shot destroys it, after which a new mine is spawned.
 * UFOs (saucers and satellites): UFOs will appear periodically. They come in 3 different colours: red, green, and white. UFOs will shoot either at the player's ships or in a random direction, with the exception of when there is a pair of red and green saucers on the screen simultaneously, in which case they will shoot between each other. Initially, only red and green saucers appear. After enough space objects have been eliminated, only white satellites or red-green saucer pairs will appear. UFOs appear less frequently in level 1. Green saucers are faster, fire more frequently, and aim more at the player's ships (as opposed to firing in a random direction) than red saucers. White satellites do not drop power-ups, and may otherwise behave like either a red or green saucer. By level 10, 2 saucers of the same colour can arrive on the screen together.
 * Stars and fuzzballs: Stars start appearing in a level if the player has taken too long. They enter from one side of the screen and make their way towards the other with progressively increasing speed. They also appear in the bonus stages between levels with increasing starting speeds as you reach higher levels. Once a star leaves the other side of the screen, it will re-enter the screen as a homing fuzzball. Therefore, try to destroy stars before they could exit the screen.

Game options
There are 4 gameplay options you could choose from: Intermediate/Advanced coupled with single ("Fighter")/double ("Space Station") ship.

In a Space Station game, your hitbox is larger, but you also get twice the firepower.

The following table outlines difficulty differences:

Atari 2600 version
2 years after the release of the original Space Battle, the "Atari 2600 version" was released with some gameplay differences. The Atari stylistic focus of this version is transparent overlapping sprites. Additionally, the Atari console screen has been improved from the version seen in Little Red Riding Hood's Zombie Hunt. The Atari 2600 games Asteroids, Space Rocks, and Space Duel on the Atari Flashback 2 served as this version's main influences. Changes from the original Space Battle are listed below.

Improvements/neutral changes include:
 * Slower ship acceleration after players voiced their opinions about the original being too fast.
 * Space splitting objects do not spawn in the middle section of the screen.
 * Power-ups are chosen before starting the game, and the player is equipped with it from the start.
 * Overall difficulty decrease, especially in the Intermediate difficulty mode, after a friend of Tangent's commented that they found Space Battle to be one of Tangent's harder games. The Advanced mode is largely unchanged in its difficulty.
 * Changes in enemy behaviour during the bonus levels.
 * Players are given 5 lives at game start and an extra life is given every 2 bonus levels survived, unlike in the original remake where 10 lives are given at start and 1 extra life is given every 5 rounds regardless of whether the player survives the preceding bonus level.
 * Player ship rotation now works differently in the Space Station (tethered ships) mode to keep with the 2600 theme.
 * The game over screen is now an endless (until player input) Atari demo screensaver.

Downgrades: The game options are as follows:
 * The next wave immediately sets up after a bonus level ends (and the player ship’s position remains constant). Though you can’t spawn immediately after a wave starts so that is one of the way the game mitigates it (as well as splitting objects not spawning in the middle section).
 * Graphics are downgraded. There are only 2 types of splitting objects and most graphics turn transparent when they overlap (flicker + phosphor).
 * Numerous effects are removed to keep with the 2600 theme.
 * Reduction in number of sound effects used.

Trivia
For the Atari 2600 version:
 * The title screen is based on that of the original arcade game, with the year being written in Roman numerals.
 * Tangent's favourite part of the original arcade game is the saucers that were described as "shooting each other" on Strategy Wiki. Tangent had not experienced that in the Atari 7800 hack, which is a reason Tangent made sure to bring that aspect over (even prominently on the title screen) to the remake.
 * The names of the dangers in the game are taken from the arcade game manual.
 * The original 4 options of the arcade game that's selectable by the player are: 1 player single ship, 1 player linked ships, 2 players independent ships, and 2 players linked ships.
 * The player may spawn only when they're ready. There is no time limit that force-spawns the player's ships.
 * The power-up icons are inspired by Game Maker drag and drop icons.
 * While the question marks are rounded in the instructions screen, they are made of straight lines in-game.
 * The difficulty switches and select switches all affect the game.
 * At first it seems like there are many objects on the screen, but this kind of thing was seen possible in SpiceWare’s Space Rocks, a homebrew for Asteroids/Asteroids Deluxe. Even if there’s still far too many, at least it’s not completely off. Note that overlapping sprites turn transparent, which is an imitation of the flickering technique with the “phosphor” effect. This is also seen in Space Rocks.
 * - The sounds and overall aesthetics are mostly inspired by the Atari Flashback 2 version of Space Duel, with some influences from elsewhere, including Asteroids and Space Rocks on the 2600, and a tiny bit from the Atari 7800 Space Duel hack from PacmanPlus.


 * The dual ship feature may be explained away by the “sprite cloning” feature that’s possible for the Atari 2600, as seen in games like Combat, where up to 3 objects using the same sprite may move in unison.