Akkanvader/Gameplay

Controls

 * Joystick: Use the 2-way joystick, to direct your chosen ship along the bottom of the screen; none of them can wrap round from one side to the other.
 * Firing Button: Use this button to make your chosen ship fire bullets up at the invaders; holding it down charges the shot (much like Apollo's sword in Namco's Phelios), and upon releasing the button the ship fires a more powerful shot up at the invaders. Every ship has their own unique type of shot.
 * 1 or 2 Player Buttons: Push these buttons to begin the game as player 1 or player 2.

First-player pilots
Sayo-Chan originally appeared in KiKi KaiKai back in 1986, and has also appeared in the seventh stage of Space Invaders DX's "Parody Mode" in 1994; for the US version, Kusai-Wa 1 was renamed to "Toilet I", Poribaketsu 1 to "Bucet I", Wanko to "Harry", Clyde misspelled as "Cride" and Goriyaku 1 was renamed to "Amulet I". The descriptions of the ships that appear during the attract mode are also changed to feature badly-translated "Engrish" phrases.

Second-player pilots
In the US version, Kusai-Wa 2 was renamed to "Toilet II", Danboru-Bako 2 to "Corrugated Carton II", Nyanko to "Nancy", Bonnie misspelled as "Bonny", and Kaiun Ni was renamed to "Amulet II"; this also meant that the character of Nyanko was changed from a male (the only one on 2P side), to a female.

Regular Invaders
The alien invaders still behave the same (again); they remain in formation (as they advance towards the bottom of the screen). The entire formation will either circle around as they move downwards, move to the right or the left until the far column reaches the side of the screen then drop down and move back towards that other side of the screen, or move downwards - and, the lowest invader of every column shall fire bullets down to the ground (and you will receive 10 extra points for every one you block, or for those that cannot be blocked, attempt to). If any one invader manages to reach the bottom of the screen, both players will die immediately as the Katakana text Inbēdo (インベード) for the Japanese version or the English text "INVADE" for the US version, appears on the screen (but, like in Majestic Twelve, your game will not end; the invaders will just return back to their original starting positions).

Bonus Invaders
These types of invaders only appear on the "Bonus Stages" (4, 10, 18, 25 and 31); they will fly into view from the left side, right side or top of the screen and you can kill them, for bonus points. At the end of the stage, the amount of bonus points you received for the killed Bonus Invaders will get tabulated.

Boss Invaders
World 1 (Stage 5): Once your two chosen ships have stopped moving on forward, the first Boss Invader will drop down into view from the top of the screen and speak the threescript text Kondo ha, 'bosu' no oresama ga aitedā!! (今度は、「ボス」のオレ様が相手だー!!) in the Japanese version, or "THIS TIME, I, THE BOSS FIGHT AGAINST YOU!" in the US version; he will now start flying around up above you while spewing a volcanic hail of bullets and bombs down at you (the latter of which can get blocked, for extra points). He'll then throw two bowling balls down at you, and spew out twenty-four small versions of himself - which will adopt a vertical formation as they descend towards the bottom of the screen, so you shall have to kill them as well. Once you have fired out enough shots at him to defeat him, he will explode, and speak the Hiragana text Chikushō, oboe terō!! (ちくしょー、おぼえてろー!!) in the Japanese version; you'll then receive 10000 bonus points, as your chosen pilots speak the Kanji/Hiragana text of ''Rakushō! Chō rakushō! Pīsu!'' (楽勝! ちょー楽勝!! ぴいすっ!) (in the Japanese version), or "WALKAWAY!! A VERY EASY VICTORY!" (in the US version). You'll now proceed to World 2, which appears to be based on food.