[[quoteright:320:http://static.tvtropes.org/pmwiki/pub/images/srb20013_4527.png]]
[[caption-width-right:320:[[DevelopmentHell When it's done.]]]]
''[[http://www.srb2.org/ Sonic Robo Blast 2]]'' is a 3D freeware fangame based on the SonicTheHedgehog games and created on the ''VideoGame/{{Doom}} Legacy'' engine. It was started in 1998, and has been in development ever since.

It is a sequel to ''Sonic Robo Blast'', a very crude fangame by a user named Sonikku. It was created in the ''Klik And Play'' game making program, and was very primitive and quite buggy. Despite this, the game is full of secrets, and is renowned for being one of the first Sonic fangames ever created.

It was started in 1998 and was intended to be a 2D game similar to its predecessor. This concept was scrapped when the team (at the time made up of users [=SSNTails=] and Sonikku) decided to make the game using the 3D Doom Legacy engine. Early tech demos featured basic Sonic gameplay but still showed its Doom origins. As more releases came out, the game consistently became more Sonic-like, as well as adding online netplay including Co-op in the single-player levels, a unique Deathmatch system, CaptureTheFlag, and racing.

In 2005, the inaccurately titled "Final Demo" Version 1.09.4 was released, and development was considered to have stalled for 4 years. In 2009, Version 2.0 was released and was the biggest update to the game, containing 7 new single-player levels, an overhauled Match system, and a lot of new options for level-developers. The current version, 2.1, was finally released in mid-March of 2014 after 4 long years of wait, containing level updates, graphics revamps, new stages (single and multiplayer) and more.

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!!This game contains examples of the following tropes:
* AscendedFanboy: Two longtime developers ([=SSNTails=] and Spazzo) of [=SRB2=] have gone on to monetize their hobby with [[http://spaddlewit.com Roly Poly Putt]], an app for iOS. Some of the game's art might look a bit familiar, however...
* AllDesertsHaveCacti: Arid Canyon Zone, justified as it is inspired by [[WileECoyoteAndTheRoadRunner Road Runner cartoons]] and the Grand Canyon. Averted by the multiplayer stage Desolate Twilight, which has no cacti whatsoever.
* AllThereInTheManual: Knuckles' purpose for helping Sonic is only stated on the game's website. ([[RememberTheNewGuy In a somewhat shoehorned fashion, too.]])
** There exists DummiedOut cutscene data that was meant to be used after [=GFZ3=] to insert Knuckles into the story.
* BatmanCanBreatheInSpace: Somehow ''averted''. Going into any areas in Egg Rock Zone that are in open space will begin a countdown much like in the underwater levels that appear seconds before the player drowns. With space, the countdown timer begins immediately.
* BonusLevelOfHeaven: [[spoiler:Aerial Garden Zone, unlocked by completing the main game with all emeralds.]]
* BossRemix: Inverted; the music for Castle Eggman Zone is a remix of the boss theme.
* BottomlessPits: They start appearing at Deep Sea Zone. Later, you'll see that the final part of Arid Canyon Zone, for example... is [[SarcasmMode hilarious]]. And Egg Rock Zone plays more like a [[NintendoHard Mega Man level than a Sonic level.]] It even includes a few disappearing platform puzzles!
* BrutalBonusLevel: [[spoiler:Azure Temple Zone, a very difficult underwater level unlocked by completing Aerial Garden Zone]]
** [[spoiler:The special stages have Black Hole Zone, which]] can only be unlocked by A ranking the other 7 special stages, a feat in itself.
* CutSong: Mine Maze Zone, Rocky Mountain Zone, and Doomship Zone (among many other themes) still have their music buried within the game. Subverted, because anyone can use these in modifications.
** The Pre-2.1 special stage music has become this with the advent of the NiGHTS-themed special stages in Version 2.1.
* DeathMountain: Rocky Mountain Zone would have been this as well as ThatOneLevel until it was essentially turned into Arid Canyon Zone, which still fits the bill - rockslides, crumbling terrain, [[EverythingTryingToKillYou chunks of the ceiling]] that conveniently collapse when you cross under them, and of course, [[BottomlessPits some lethally steep dropoffs]].
* DifficultySpike: Largely due to the fact that the game is incomplete, but Egg Rock Zone counts as a spike up the unsuspecting player's rear end, as you leap from the sixth zone to the eighth/ninth zone in an instant. In this sense, Red Volcano Zone is something of a BreatherLevel before the game starts trying out dozens of ways to [[OneHitKill destroy your sanity]].
** The sixth Special Stage is an enormous leap in difficulty compared to relatively hazard-free first five.
* DummiedOut:
** Mine Maze Zone was planned to be a DugTooDeep level before being merged into Arid Canyon.
** Additionally, there are several beta rooms inside Egg Rock Zone Act 2 accessible only with the NOCLIP command.
** The [[RespawningEnemies Chaos]] gametype was cut back in version 1.09; however, Chaos Enemy Spawns can still be placed, and it's possible to re-enable the (now half broken) gametype with EXE modding.
** Christmas and [[VideoGame/SonicAdventure Adventure]] modes were removed in 2.0. The former caused lots of consistency errors in netgames, the latter was only a test and not particularly well liked.
** Some of the textures and flats from [[InvaderZim Zim's Base Zone]] still exist, too.
** The original special stage music from Versions 2.0 and earlier has been replaced with songs from the Mystic Realm soundtrack for the new NiGHTS-themed special stages in Version 2.1. The original song is still in the game's files as an unused song, however.
** The old version of Brak Eggman that appeared in a scrapped version of Egg Rock Act 3 still exists as an object in the game.
* EasterEgg: The Ultimate Cheat, which [[spoiler:closes the game when activated]]; the [[spoiler:[[GratuitousDiscoSequence Disco Room]]]] in Egg Rock Zone; and literal easter eggs which only appear in old versions of the game.
* EliteMook: You know those silly, weak Crawlas running around the early stages? Well, the hovering, hopping, lunge-attacking Crawla Commander is neither silly nor weak. It's also the only enemy that takes two hits to smash, changing its attack pattern when damaged.
** WeaksauceWeakness / SuicidalOverconfidence: Stand still and rev a spindash. Wait.
* EmbeddedPrecursor: An incomplete remake of [=SRB1=] (with no bosses yet) can be unlocked in the game. It serves as something of an amusing reminder of the more primitive days of Sonic fangaming.
* EternalEngine: Techno Hill Zone, Egg Rock Zone, and several multiplayer stages with those themes.
* ExactlyWhatItSaysOnTheTin: There's the Castlebot Facestabber, which appears in Castle Eggman Zone, is a robot, and stabs your face.
* FreewareGames
* FunWithAcronyms:
** The '''S'''tupid '''D'''umb '''U'''nnamed '''R'''obo '''F'''ish is exactly what you would expect it to be.
** An enemy called the '''B'''ird '''A'''ircraft '''S'''trike '''H'''azard, that flies at a high speed towards you.
* GangUpOnTheHuman: Approach a group of enemies and then leave them unharmed. Then watch as they form a line and go after you. Also, never do this to a group of flying enemies. [[BottomlessPits Just don't.]]
* GameMod: The game itself is an open-source mod of the ''Doom Legacy'' engine, and the community promotes user-created levels and characters with a section for releases on the official forums and a bimonthly contest for level designers that anyone can take part in. One of the most well known mods is [[http://mystic.srb2.org/mrealm/ The Mystic Realm]], which adds eight new zones and was made by Mystic, the current lead developer and senior community member.
* TheGoomba: Crawlas. Also, real Goombas straight from [[SuperMarioBros Super Mario Brothers]] appear in a secret level.
* GravityScrew: Egg Rock Zone, so much. Of both 'The Variable Gravity Chamber' and the 'Fun With Gravity' variety. Twisted Terminal Zone's main gimmick is this.
* GreenHillZone: Greenflower Zone, Jade Valley Zone and Meadow Match Zone. And Sapphire Falls contains Green Hill Zone textures and music.
* GuiltBasedGaming: Of the various funny phrases the game can throw at you when you try to quit, few punch as hard as "You're trying to say that [[VideoGame/SonicTheHedgehog2006 Sonic2K6]] is better than this, aren't you?"
* HailfirePeaks: Techno Hill Zone's first act is a mix of GreenHillZone and EternalEngine elements, then it goes full-out EternalEngine for the second.
* HolidayMode: There was a Christmas Mode, present from at least Demo 4 to Final Demo 1.09.4, which activated during the twelve days of Christmas (or any day of the year, when the program was launched with -xmas). Most of the game's more natural textures changed to have a more wintry feel (eg: dirt took on a frosty blue shade and grass turned into snow, while metal retained its texture), as well as changing some of the decorations in the game (flowers turning into poles and Christmas trees). Demo 4 even had a map exclusive to this mode, where you would search for Chaos Emeralds amongst Santa's workshop; this map was retained in later versions as "Emerald Hunt", available any day of the year. Christmas Mode was eventually deleted in 2.0, due to its tendency to riddle netgames with consistency errors.
* HumiliationConga: Crawlas are prone to this.
* IcePalace: Ice Palace Zone from the [=SRB1=] remake. There's also the Diamond Blizzard Zone and Frost Columns Zone match stages.
* InconvenientlyPlacedConveyorBelt: Techno Hill Zone and Egg Rock Zone feature these.
* InvincibleMinorMinion: Turrets cannot be harmed by the player at all, and can only be destroyed if the level is nice enough to provide a way to crush or submerge them.
* JokeLevel: [[spoiler:Aerial Garden Zone]] is a serious unlockable, but was initially created as a ridiculous test map to see if the engine would cry from [[spoiler:cramming 4 full acts of a Zone into a single, massive map that stretches out almost to the hardcoded map boundary]]. It proved to be playable with some tweaking, so they [[ThrowItIn threw it in]].
* KillEmAll: Eggman wastes no time reducing the citizens of Greenflower City in the intro to charred skeletons. Chew on that, [[VideoGame/SonicTheHedgehog2 Genocide City Zone]].
* LedgeBats: Egg Guards are usually an annoyance at best, but get them near a ledge and they become aggravating.
* LethalLavaLand: Red Volcano Zone. There's also a level in the [=SRB1=] remake that's simply named "Volcano Zone", which has a lava pit that flushes you right off the 2D plane, right into a bottomless pit. Infernal Cavern from the multiplayer rotation also qualifies.
* LoadsAndLoadsOfLoading: Not (usually) present in the main game, but in full effect in multiplayer. When attempting to join a netgame that has WADs the player does not have downloaded, the game will begin attempting to add each individual file to a "DOWNLOAD" folder located in the same directory as the main game. However, the download speed can be painfully slow, and if the size of one file exceeds over a few hundred kilos, the download either slows to a crawl or under most cases, '''stops completely'''. Sometimes, it won't even begin downloading the necessary file(s)!
** In netgames themselves, "join lag" (a game-wide freeze whenever someone joins the server) is pretty much unavoidable, and woe be the other players if the joiner encounters a hitch of any sort in the process.
** New in version 2.1 is the re-sync feature, which will pause the game and attempt to restore consistency to a player who de-synced rather than immediately kicking them from the game. If someone has a particularly nasty de-sync the game can be halted by re-sync attempts for several minutes.
* MacroZone: The Mini Sonic gimmick from [[SonicCD Metallic Madness]] returns in Egg Rock Zone.
* MarathonLevel:
** Egg Rock Zone Act 2 is an incredibly long and daunting gauntlet. Best stockpile lives in advance. (To make matters worse, Act 1 has possibly the largest collection of instant-death hazards in the game.)
** [[spoiler:Aerial Garden Zone. That's because it is made up of all 4 acts of Aerial Garden Zone from a popular mod, crammed into a single map. It just barely fits in the engine's limitations.]]
* NintendoHard: Egg Rock Zone will probably eat up most of your lives the first time you play it. The [[BrutalBonusLevel Hyper Levels]], a series of hidden stages, are also intended to invoke this.
* NoEnding: Granted, it's still an incomplete game.
* NonIndicativeName: Deep Sea Zone is set inside a cave. In the earliest version of the game, however, it ''is'' set in the sea.
* NotSoHarmlessVillain: In the main series, Eggman is an inept and comical villain. In this game, he starts things off by destroying a city and killing everyone in it.
* OneHitPointWonder: Per ''Sonic'' standard when you have no rings, but taken to the extreme in the hidden Ultimate Mode, which removes all rings and item boxes from the game. You also only have one life, which turns the game into an ''VideoGame/IWannaBeTheGuy''-like suicidal DeathCourse where one ''scratch'' from anything, anywhere, is a ticket back to square one.
* PalmtreePanic: Emerald Coast Zone.
* PlatformHell: The latter half of the game. Unusual controls (for newbies, perhaps) and the lack of shadows cast beneath your characters twists the knife. Also the [[CaptureTheFlag CTF]] stage [[ThatOneLevel Nimbus Ruins]], which is nothing more than a few floating platforms above a giant [[BottomlessPits death pit]].
** Most of the levels in the [=SRB1=] remake have tricky platforming. It starts in [[IcePalace Ice Palace Zone]] and gets sadistic once you get to [[ScrappyLevel Sky Lab Zone]], which fortunately is a Knuckles-only level.
* PVPBalanced: The three characters have their own strengths and weaknesses in the multiplayer modes.
** LightningBruiser: Sonic players know to use and abuse his very fast and powerful jump dash, but without a [[DoubleJump Whirlwind Shield]] he has problems climbing up stepped terrain quickly.
** WeakButSkilled: Tails is slow and not as effective as the others in a melee, but being able to fly around to nearly everywhere on a map is a plus and he makes a good sniper with the Rail Ring (or a good ''target'' for the Rail). This is an inversion of his Single Player prowess, where Tails is pretty much easy mode.
** TheBrute: Knuckles gets a faster firing (sorry, ''throwing'') speed to compensate for his average agility and other movement disadvantages. This makes him excellent for area denial or just plain spamming projectiles. Although, he's also suprisingly good at cloak-and-dagger tactics, since gliding and climbing walls [[NothingIsScarier make no sounds...]]
* SecretLevel: [[spoiler:Aerial Garden Zone, Pipe Towers Zone, Spring Hill Zone, Azure Temple Zone, Black Hole Zone]]
* ShoutOut: WordOfGod mentioned that it's not a coincidence [[UnderwaterRuins Tidal Palace Zone]] bears more than a passing resemblance to [[VideoGame/SuperMetroid Maridia]].
** A few of the devs are ''VideoGame/{{Touhou}}'' junkies, and the three ice-themed multiplayer stages all have subtle references to Cirno.
* SlippySlideyIceWorld: Oddly averted in the Single Player game. The theme gets around in multiplayer though: Frost Columns Zone, Icicle Falls Zone, Diamond Blizzard Zone...
* TheSpiny: Sharps are a conventional example, while Green Snappers are a bit different. Their tops are completely bare but are guarded by a ring of spikes that make spindashing useless.
* Main/SniperRifle: the Rail Ring, a favorite weapon of many in the multiplayer community.
* SuspiciousVideoGameGenerosity: [[spoiler:As soon as you enter the [[EasterEgg Disco Room]] in [=ERZ2=], you find two 1ups just sitting there in the corner. To say the least, you are about to need them.]]
* SidetrackBonus: As usual for ''Sonic'', this game is loaded with extra rings, shields, and emerald tokens for those willing to look.
* SpringsSpringsEverywhere: It's a Sonic game, what did you expect?
* ThisIsADrill: The Minus badniks from Arid Canyon Zone are rocket-powered green balls with a pair of drill arms which they use to [[WormSign visibly burrow through the ground,]] jumping out to attack whatever technicolor critter treads above it.
* TurnsRed: All of the bosses go into a panic phase when you've whittled them down to three hits left.
** Sharps look cute and innocent enough, as well as slow and we- [[HellIsThatNoise what's that sound?]] '''[[OhCrap OH]] [[BossInMookClothing GOD]] [[LightningBruiser AHHHH]]'''
** Subverted by the Egg Guards. Destorying their sheild causes them to change color to red and gain a speed boost, but without said shield they are little more than a slightly faster [[TheGoomba Crawla]]
* TwoAndAHalfD: The Sonic Robo Blast 1 Remake levels.
* UnderwaterRuins: Deep Sea Zone, Tidal Palace Zone, and [[spoiler:Azure Temple Zone]].
* UniqueEnemy: [[spoiler:Azure Temple Zone]] has an enemy seen no where else in the entire game; a [[spoiler: bug that gives you air when you destroy it.]]
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