[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/gigadeep.jpg]]

''GIGADEEP'' is a freeware ''Franchise/MegaMan''-like game made in 2010 by Peposoft, the maker of ''Houkaimura'' and ''Minishooter RS Delta''. It features the usual eight levels plus a fortress and a handful of playable characters. Ability upgrades can be brought at a shop, though most of them have to be unlocked first.

On the same year, Peposoft also released a ''Touhou'' fangame, ''Touhou Koukayaku - The Game'' (based on the ''Touhou Koukayaku'' fan music album), that plays similarly to this one.

A sequel was announced in 2019.
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!Tropes featured in this game:
* AWinnerIsYou: The villain's fortress explodes. The end.
* AdvancingWallOfDoom: Used twice.
* BottomlessMagazines: ''All'' weapons have infinite ammunition.
* BraggingRightsReward: The last item pack for the shop is located on a spot that requires Deep to have both his super dash and immunity to spikes, but the secret character the pack makes available isn't really worthwhile...
* CastFromHitPoints: Deep's second attack lets him toss slime around at the cost of his health.
* DeadCharacterWalking: Due to a glitch, the player always retains some control over their character after getting destroyed. This results in the player [[BeatingADeadPlayer taking damage despite being dead]] and phasing through walls. What's more, this lasts for several seconds.
%%* DefeatEqualsExplosion: Every single enemy, complete with bosses undergoing a chain reaction of destruction when defeated.
* DifficultyLevels: The game has several ranging from Very Easy to Chaos.
* DoubleUnlock: You must unlock most of the item packs for the shop and then purchase them.
* DualBoss: Two giant amoebas, and a WolfpackBoss consisting of colored robots.
* EasierThanEasy: The Very Easy setting makes the player take minimum damage from enemies.
* EasyLevelTrick: The ''Umblade Senki'' level has what appears to be an invisible developer shortcut right in the beginning that transports the player straight to Wareed. The second bonus level also has a teleporting shortcut to the boss that's intentionally left for the player to find, but it is barely hidden at all.
* EmergencyEnergyTank: Beer is used as the equivalent of E-Tanks to recover energy.
* {{Expy}}: Pappy is one of Zero, appearance-wise. He even has an alternate mode in which the only attack he can use is Zero's specific saber combo.
* GameBreakingBug: The game is quite glitchy, and sometimes in game-breaking ways. One example being the AdvancingWallOfDoom in the ninja castle level not stopping when the player picks a dialogue-triggering item.
* HarderThanHard: The game isn't exactly playable from Owata difficulty level and above, to say the least.
* HopelessBossFight: There's nothing you can do to escape the slime monster's giant laser near the end of the game, [[FissionMailed but then]] the game shows some dialogue and suddenly drops you into the final boss fight.
* HumongousMecha: One miniboss, and the final boss' final form.
* JokeCharacter: The last SecretCharacter is a OneHitPointWonder whose second attack makes him self-destruct.
* JokeItem:
** One equippable item reduces all playable characters to 1 HP.
** One item randomizes the current equipped weapon on every frame and another one disables it. The first increases the current bolt amount whenever an area loads and the second raises it every few seconds, so both can be used to clear out the item shop as soon as possible.
* KaizoTrap: It is possible to lose a boss fight after winning by either using a self-destructing attack or jumping into spikes. Even if you delay it such that the "teleporting out" animation plays, the death will still take priority over defeating the boss.
* {{Ninja}}: Mooks who scream "NINJAAAA!" as they attack you.
* RiseToTheChallenge: Used in the fire level, and then several times later there is also a rising pool of acid.
* RubberBandAI: One AdvancingWallOfDoom speeds up if you run away from it fast enough.
* SecretCharacter: Three -- a ninja, Pappy with a three-hit saber combo and some weird dude.
* ShoutOut: One difficulty level is named "Owata", after the PlatformHell game that inspired ''VideoGame/IWannaBeTheGuy''. Oddly, it isn't the last difficulty level...
* SpikesOfDoom: They deal instant death as one might expect, but there is a item for permanently negating that.
* OptionalBoss: There are two levels unlocked along the way that don't seem to be related to the main story. Curiously, one of them [[CrossoverCameo features]] Wareed from ''VideoGame/UmbladeSenki'' as it's boss.
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