These are a series of cards Konami released based on characters in their Gradius video game series and other "shoot 'em up" games. These include player-controlled ships, support items, enemies, and bosses. Certain cards were created solely for the Yu-Gi-Oh card game with their design based upon the Gradius games. The majority and most notable of these monsters are LIGHTMachines with 1200 ATK. Therefore, much of their support can be found in Structure Deck: Blitzkrieg of the Mechlight Dragons.
A Gradius Deck revolves around the use of the cards "Gradius" or "Victory Viper XX03" along with their support cards. The main strategy is to protect your monsters from traps with the effect of "Jade Knight" and boost them all with cards you can activate during damage calculation. The majority of the Deck's monsters have effects that trigger whenever it attacks and destroys an opposing monster; these effects involve increasing their own ATK, destroying opposing cards, and especially summoning more monsters. As a result, a Gradius Deck operates under a Swarm/OTK hybrid, which is augmented by additional ATK-boosting cards such as United We Stand. Another effective strategy is to utilize cards that drop opposing ATK scores, such as Gearspring Spirit.
Due to having initially low Original ATK on a majority of its monsters, so this Deck must have a counter ready every turn as it is vulnerable to being overrun by large opposing beaters.
A variation on this Deck reached the SHONEN JUMP Championship Nashville 2010, using cards like "Honest" (before it became Limited) and "Creature Swap". 
The mass swarming of this Deck provides the opportunity to rapidly Synchro Summon and Xyz Summon. The primary monsters are all Level 4 Light monsters, allowing Lightwave Tuning to be an option. However, one might feel hard-pressed to invest largely in both Synchro and Xyz strategies while maintaining an appropriate Deck size or Card Ratio.
If one wishes to incorporate Gradius, the player has access to the many support cards that come with being a low-ATK Normal Light Machine. A pair of Gradius may be searched using Rescue Rabbit, which can be used to Xyz Summon Gear Gigant X to search another Machine from the Deck or Starliege Paladynamo to overcome a difficult monster. Gradius' Option is a monster that can be automatically summoned when Gradius is out, and by using a combination of a Level 1 Tuner such as Mono Synchron or Unknown Synchron as well as Lightwave Tuning, it is plausible to summon Shooting Star Dragon the opening turn. The player may also wish to incorporate other Normal Machines to supplement Rescue Rabbit, such as the Tuner Genex Controller or the high-ATK Mechanicalchaser, or any other possible Normal Machine. Keep in mind that since Genex Controller and Mechanicalchaser are both Dark monsters, it highly increases the playability of Black Luster Soldier - Envoy of the Beginning.
All plays should be focused on swarming and increasing ATK power. Both Gradius and Victory Viper have monsters that can copy their ATK, so equipping these monsters with United We Stand can be very beneficial, along with other ATK-boosting cards such as Honest. Other powerful Equip Cards for Machines are Mage Power, Fighting Spirit, and Break! Draw!
Without their ATK-boosting cards, these monsters are vulnerable to high-ATK monsters. For these impenetrable monsters, simply take them with Creature Swap. This steals an opposing high-ATK monster while giving your opponent a low-ATK monster that your jets can easily eradicate. Jade Knight is an especially potent Swap, as you will still obtain its searching effect even if it is destroyed under your opponent's control. Although not a best-case scenario, if your own jet is destroyed by battle, it will still activate an effect so long the other monster is destroyed by battle as well (this is because the jets do not require the opposing monster to be sent to the Graveyard and occurs immediately after damage calculation).
This deck presents some similarities to the popular Lightsworn Deck, as it needs a lot of Mill effects to have a lot of Machine-type monsters in the Graveyard and on the field to use the effect of Cyber Eltanin to clear your opponent's field and attack it directly for an OTK, but be careful, your opponent's Spells & Traps won't be destroyed, so the use of Heavy Storm or Counter Trap Cards can totally clear your opponent's field or save you from devastating effects like Mirror Force, Magic Cylinder, or Torrential Tribute.
Additionally, this deck presents some advantages to the Lightsworn Deck, the first one is that the player using this deck can see what to discard, since cards are discarded from the hand and not from the top of the deck, and also this deck is almost immune to "Bottomless Trap Hole" and "Messenger of Peace", but it still having a lot of ATK because of the using of "Honest" and cards like "Beckoning Light" to recover the Honests and send more spaceships to the Graveyard.
If "Cyber Dragon" is in this deck, "Chimeratech Fortress Dragon" can also be used as an emergency card in the extra deck. Also, only a few Trap Cards are used in this deck, only the staples ("Solemn Judgement" and "Torrential Tribute") and semi-staples ("Raigeki Break") and the "Beckoning Light" because it is a great engine in the functionality of this deck.
Midday Constellation is a Booster Pack in the Yu-Gi-Oh! GX Tag Force series whose contents are made up of cards from Konami games. The pack is unlocked by entering the Konami Code at a certain point in the game, and, depending on the game, costs either 5730 or 573 DP (573 is a number regularly self-associated with Konami due their own Goroawase number).