Skulldash

Skulldash is a megawad and time-trial styled gameplay mod for GZDoom (3.2.0 and higher) created by Joshua O'Sullivan (Dragonfly). The original version, containing 32 levels, was released on 22 October, 2015, and ran on the Zandronum source port. This first release went on to win one of the 22nd Annual Cacowards.

In 2017, an expansion pack, entitled Skulldash: Expanded Edition was released, allowing the mod to be played in GZDoom, and featuring an additional eighteen levels created by O'Sullivan and various mappers from across the Doom community. The mod is intended to be played using the OpenGL renderer, with the effects of the software renderer ranging from sub-optimal visuals to major graphical glitches on some maps.

Skulltokens
In Skulldash, the player is tasked with reaching the exit of each level within a set time limit, collecting tokens (officially referred to as skulltokens) along the way in addition to fighting monsters to reach as high a score as possible. Each level requires the player to collect 75% of all skulltokens in the map. Most skulltokens are white in colour and add 100 points to the player's score, though some different-coloured variants are also included, each performing a different function when collected:


 * Green skulltokens provide the player with 25 armor points, and add 1,000 points to the player's score.
 * Red skulltokens provide the player with 25 health points, and add 1,000 points to the score.
 * Blue skulltokens add an extra five seconds to the remaining time, and add 500 points to the score.
 * Golden skulltokens are found rarely, but give the player 100 armor points, as well as adding 50,000 points to the score.

The exit area of the map will not open until the player has met the 75% collection requirement. If the player manages to collect every skulltoken, they will be rewarded with a high value health-item (usually a soulsphere or megasphere) at the exit, and their score for the level will be doubled. If the player fails to reach the exit in time, they will be automatically killed and have to restart the level.

Monsters
Skulldash features the original Doom II monster cast, unchanged from their original behaviour, as well as some new additions. Killing monsters will add to the player's score.

Score values of original monsters

 * Zombieman - 100 points
 * Shotgun guy - 300 points
 * Imp - 400 points
 * Stealth imp - 500 points
 * Lost soul - 500 points (including those spawned by pain elementals)
 * Demon - 600 points
 * Stealth demon - 700 points
 * Spectre - 700 points
 * Chaingunner - 900 points
 * Cacodemon - 2000 points
 * Revenant - 2500 points
 * Hell knight - 2700 points
 * Stealth Hell knight - 2700 points
 * Arachnotron - 3000 points
 * Mancubus - 3000 points
 * Pain elemental - 3500 points
 * Baron of Hell - 5000 points
 * Arch-vile - 7500 points
 * Spider mastermind - 15000 points
 * Cyberdemon - 20000 points
 * Commander Keen - 750 points

Custom monsters
All custom monsters except the bosses, the shadow, grell, flesh spawn, blood skull, and gem turret are taken from Skulltag, modified only to implement the score mechanic.
 * Shadow:A dark, translucent imp-like monster with a fast movement speed. The shadow launches red projectiles with relatively low damage, and will not stop doing so until the player moves out of its line of sight. It has 80 health, and is worth 400 points.
 * Dark imp:A dark-skinned imp. It launches a fast-moving blue and purple projectile that deals similar to damage to the regular imp. It has 120 health and is worth 800 points.
 * Flesh spawn:Flesh spawns are small pink, spherical flying demons that could be described as the larval form of the cacodemon. Their only feature is the large mouth, which they use to attack. They can charge at the player similar to lost souls, or they can launch a miniature cacodemon projectile which deals 2-16 damage. They have 50 health and are worth 1000 points.
 * Blood skull:These flying skulls are covered in blood, which can be seen dripping to the floor beneath them. They attack frequently, launching a red projectile that deals 3-24 damage. They have 120 health.
 * Blood demon:Blood demons can be distinguished from regular demons by their darker colour. It has 300 health - twice that of the demon - but is functionally the same. Blood demons are worth 1200 points.
 * Grell: Grells are brown airborne demons similar in appearance to the cacodemons from Doom 3. They have 300 health and attack by launching a small green projectile that explodes on impact with the player, releasing a noxious green gas that deals damage over time. They are worth 2500 points.
 * Cacolantern:This cacodemon variant is marked by its orange skin. It fires a light blue projectile that deals the same damage as its original counterpart, but travels at twice the speed. The cacolantern has 800 health - twice that of the cacodemon - and is worth 3000 points.
 * Super shotgun guy:An addition to the zombie roster that is self-explanatory in function. Identifiable by their black and green armor, super shotgun guys are very dangerous at close range, dealing up to 75 damage before armor. They have 120 health and are worth 3500 points. Upon death, the super shotgun is dropped.
 * Hectebus:A dark grey mancubus. Like its original counterpart, it will attack three times in a single action, however it instead launches bright green fireballs that move 10% faster than those of the original, and deal 50% more damage. It also fires more fireballs at once, with a spread of four fireballs in each of the first two shots, and five in the third. The hectebus has 1200 health - twice that of the mancubus - and is worth 7500 points.
 * Belphegor:An upgraded baron of Hell that launches a volley of three projectiles, the same behaviour as a cyberdemon. The projectile differs only from the regular baron's in its speed, moving 33% faster. The belphegor has 1500 health, and is worth 10000 points.
 * Abaddon:This is a cacodemon variant with a black and dark grey appearance. It shoots two orange projectiles in succession, which have twice the speed and damage as the regular cacodemon projectile. Abaddons have 1200 health - three times that of the cacodemon - and are worth 12500 points.
 * Gem turret: Gem turrets appear as support for the seraphim. They are stationary, and attack by launching a single white projectile identical to that of the seraphim's, with a moderate firing rate. They have 50 health and are worth 500 points.

Bosses

 * Lava demon: This is the first boss monster, encountered at the end of tier two. It is a bright red-orange humanoid seemingly made entirely out of lava. It has 6000 health and is worth 100000 points.
 * Dark inquisitor: This is the second boss monster, encountered at the end of tier three. It is based on the inquisitor from Strife. It has 6000 health and is worth 5000 points.
 * Gate keeper: This is the third boss monster, encountered at the end of tier four. It takes on the appearance of the cycloid emperor from Duke Nukem 3D, with jet black skin. It has 6000 health and is worth 5000 points.
 * Overlord: Encountered in the final level of the main set, this airborne boss resembles a six-armed pain elemental, with black skin. It has 10000 health and is worth 10000 points. It has multiple attacks and its behaviour changes as it loses health.
 * Seraphim: Encountered in the community set, this boss is a winged knight in white armor. It has 27500 health and defeating it will reward the player with 2.5 million points. The seraphim has multiple attacks, and its behaviour changes over time.
 * Dark cardinal: Encountered in the community set, this is a flying top-half of a cyberdemon, with 20000 health. It has black skin and magical blue fire takes the place of the demon's lower half. Upon beating the cardinal, the player will receive one million points. The cardinal has multiple attacks and its behaviour changes over time.

Other custom things
In addition to the monsters, Skulldash contains the content definitions for other custom things from Skulltag, namely all weapons, spheres and runes, and also the red armor, which gives 200 armor upon pickup and absorbs 80% of damage.

Tier system
The levels of Skulldash are grouped into mini-episodes referred to in-game as tiers. There are five main tiers, plus an additional community tier that was added in the expanded edition. The tiers are scattered around different parts of the hub level, which the player is returned to after completing a level. Each tier is initially locked; the player must complete a tutorial level in order to unlock tier one. Every level in tier one must be completed in order to unlock tier two, and so on, however, the levels within a tier can be completed in any order, with the exception of boss maps, which themselves are locked until the completion of the tier's normal maps. Each tier also includes a bonus level, which is unlocked after the tier has been completed, but is not required to progress in the game.

The community tier is considered separate from the main game, and can be accessed as soon as the tutorial has been completed.

Level list
All levels designed by Joshua O'Sullivan (Dragonfly) except where noted otherwise:


 * The Hub
 * MAP27: Credits!
 * Level 00: Educational
 * Tier One
 * Level 01: Yellow Submarine
 * Level 02: Ancient Treasure
 * Level 03: Clifftop Base
 * Level 04: Frostbound by Joshua O'Sullivan and Slyor 64
 * Bonus 1: Gotta Go Fast!
 * Tier Two
 * Level 05: The Citadel
 * Level 06: Abandonment
 * Level 07: Time Warp
 * Level 08: Water Station by Capt. J3
 * Boss 01: Lava Sanctuary
 * Bonus 2: The Shocker
 * Tier Three
 * Level 09: Jungle Altar
 * Level 10: To Hell and Back
 * Level 11: Liquidation
 * Level 12: Black Death
 * Boss 02: Emerald Inquisition
 * Bonus 3: Vibetech
 * Tier Four
 * Level 13: Feelin' Blue
 * Level 14: Heated Heights
 * Level 15: Divider
 * Level 16: Maltreatment
 * Boss 03: Keeper of the Gate
 * Bonus 4: The Nightclub
 * Tier Five
 * Level 17: Medieval Madness
 * Level 18: Sector 13.37
 * Level 19: Treetop Tokens
 * Level 20: Strength
 * Final Boss: The Bloody End
 * Level 21: Invasion!
 * Community Tier
 * by Daniel Gimmer (Tormentor667)
 * by Gianluca Cilento (Remmirath)
 * by Gianluca Cilento (Remmirath)
 * by Dreadopp
 * by James Paddock (Jimmy)
 * by Gianluca Cilento (Remmirath)
 * by AtroNx
 * by Devon Barnett (Xyzzy01)
 * by kyle2959
 * by Ben Mansell (Bauul)
 * by Gianluca Cilento (Remmirath)
 * by Poohlyash
 * by Gianluca Cilento (Remmirath)
 * by Gianluca Cilento (Remmirath)
 * by Ben Mansell (Bauul)
 * by Gianluca Cilento (Remmirath)
 * by Poohlyash
 * by Gianluca Cilento (Remmirath)
 * by Gianluca Cilento (Remmirath)

Soundtrack

 * The Hub: MIDI rendition of "Fremont Street" from 
 * Credits:
 * Level 00: "To Far Away Times" by (from )
 * Level 01: MIDI rendition of the Skull Rock theme from , by
 * Level 02: MIDI rendition of "Battle 3" by (from )
 * Level 03: MIDI rendition by of "Quad Machine" by (from )
 * Level 04: MIDI rendition of "Ice Valley" by (from )
 * Bonus 1: MIDI rendition of "Diamond Dust Zone" from  (Genesis version)
 * Level 05: "Seasons of Insanity" by James Paddock (Jimmy) (from the Plutonia MIDI Pack)
 * Level 06:
 * Level 07: TNT: Evilution MAP04/13/29 theme
 * Level 08:
 * Boss 01:
 * Bonus 2:
 * Level 09: MIDI rendition of "Chance for a Big Reversal" by (from )
 * Level 10:
 * Level 11:
 * Level 12: MIDI rendition of "Blinded by Light" by (from )
 * Boss 02: MIDI rendition of "Cell Games Arena Stage" by (from )
 * Bonus 3:
 * Level 13: MIDI rendition of "Substance Skateboarding" from 
 * Level 14: MIDI rendition of "Psychotron" by
 * Level 15:
 * Level 16: "Infinite" by Tom Mustaine (from TNT: Evilution)
 * Boss 03: MIDI rendition of "Silent Night, Bodom Night" by
 * Bonus 4: MIDI rendition of "" by
 * Level 17: MIDI rendition of "The Chase" by (from )
 * Level 18: "Horizon" by Tom Mustaine (from TNT: Evilution)
 * Level 19: MIDI rendition of "Dorter Trade City" from 
 * Level 20: MIDI rendition of "Big Shot XL" from 
 * Final Boss: "Mist Ache" by Lee Jackson (from Rise of the Triad)
 * Level 21:
 * MAP33: "Hate Machine" by James Paddock (Jimmy)
 * MAP34: "Caught in the Shadows" by James Paddock (Jimmy)
 * MAP35: "Illuminary Obelisk" by (from )
 * MAP36: "Manoria Cathedral" by Yasunori Mitsuda (from Chrono Trigger)
 * MAP37: "Godhood Pt. 7 - Temple of the Unforgiven" by James Paddock (Jimmy)
 * MAP38: MIDI rendition of "Underworld 2" from 
 * MAP39: MIDI rendition of "BotMCA #10" by (from Unreal Tournament)
 * MAP40: "Mistery" by Valery Belozercev (Butch) (from Brave Dwarves 2)
 * MAP41: "Wasteland" by James Paddock (Jimmy) (from Plutonia 2)
 * MAP42: "Ankle Grinder" by James Paddock (Jimmy)
 * MAP43: "Lost Painting" by (from )
 * MAP44: "Osmose" by James Paddock (Jimmy)
 * MAP45: MIDI rendition of "ZX" by Ruslan Ermolin (from ZX Spectrum Doom)
 * MAP46: "Bombshell" by James Paddock (Jimmy)
 * MAP47: "Night Air" by James Paddock (Jimmy)
 * MAP48: MIDI rendition of "Oppression" from 
 * MAP49: MIDI rendition of "Tidal Tempest Present" from  (Japan/Europe edition)
 * MAP50: "Set it Ablaze" by James Paddock (Jimmy)
 * MAP51: "Dark Halls" by Robert Prince (from Doom)


 * Title screen: Opening theme to