PROJECTILE BOOST - Parry a Shotgun pellet into an enemy.

ARSENAL - Kill an enemy with multiple different weapons. Variations of weapons count as different. Damage from certain types of enemies (such as friendly fire from malicious faces) also counts. Combo attacks (such as shooting core with a revolver) do not count.

RICOSHOT - Ricochet any Revolver shot off one or more Coins. Score is calculated by total number of coins ricocheted (or more accurately the power of the final coin shot due to factors like Coin Punching and Deadcoining) multiplied by 15.

ULTRARICOSHOT - Chain a hitscan projectile other than the Revolver's primary fire off of one or more Coins. Reflected enemy hitscan attacks also count. Score is calculated by total number of coins ricocheted multiplied by 15.

COUNTERRICOSHOT - Ricochet the Revolver's primary fire off of one or more Coins with at least one coin in a red counter state from V2's revolver shots. Score is calculated by total number of coins ricocheted multiplied by 15.

ULTRACOUNTERRICOSHOT - Ricochet a hitscan projectile other than the Revolver's primary fire off of one or more Coins with at least one coin in a red counter state from V2's revolver shots. Score is calculated by total number of coins ricocheted multiplied by 15.

CONDUCTOR - Shoot an enemy filled with Nails using the Electric Railcannon. Gain 1 style point per nail up to a total of 90 nails

BIPOLAR - Kill an enemy with Nails orbiting between 2 magnets.

ATTRAPTOR - Kill an enemy with Nails clustered around a magnet.

SERVED - Parry a Landmine into an enemy.

LONG WAY DOWN - Drop an enemy's corpse off the Earthmover in ( 7-4: ...LIKE ANTENNAS TO HEAVEN )

BOILED - Make an enemy or its corpse fall into the Phlegethon (AKA the boiling blood river) in ( 7-2: LIGHT UP THE NIGHT )

FOR THEE - Make an enemy or its corpse get crushed by the falling watchtower in ( 7-2: LIGHT UP THE NIGHT )

M.A.D. - Kill an Earthmover or any other enemy by letting the timer run all the way down.

QUICKDRAW - Shoot an enemy immediately after switching to the Revolver or Shotgun.

NAILBOMBED - Hit / Kill an enemy with the nails scattered from a magnet exploding or with a sawblade punched out of its orbit around a magnet.

FIREWORKS - Launch and explode an enemy in midair.

OUT OF BOUNDS - Make an enemy fall out of the level.

FALL - Make an enemy fall into a bottomless pit or void.

FISTFUL OF DOLLAR - Parry a Coin into an enemy.

INSTAKILL - Shoot a Streetcleaner's explosive tank.

DOWN TO SIZE - Parry The Corpse of King Minos' punch.

ZAPPED - Have an enemy fall into a kill plane in the Cyber Grind.

HOMERUN - Lure a Drone or the Mysterious Druid Knight (& Owl) in, or hook into a Virtue with the Whiplash, then quickly kill it with a punch.

CATAPULTED - Have a magnet kill an enemy filled with nails by flinging them into the ground.

CANNONBALLED - Kill an enemy using the S.R.S. Cannon's alt fire, parry the Virtue's orb after it dies to an enemy, parry the Insurrectionist's Malicious Face back to it and kill it, or parry a Drone into Malicious Face and kill it.

MAURICED - Kill an enemy by crushing them with the falling corpse of a Malicious Face. Killing an enemy with the Malicious Face-shaped rolling boulder in 4-S also gives this bonus.

LANDYOURS - Parry a Landmine into the Guttertank (or Big Johninator) that placed it.

PANCAKED - Kill an enemy by crushing them with the falling corpse of a Gutterman.

ROUND TRIP - Ride a Guttertank's rocket back into itself (without the Whiplash).

LOST - Make an enemy or its corpse fall deep into the Wood of the Suicides in ( 7-3: NO SOUND, NO MEMORY )

SCRONGLED - Enemy killed by the red substance found in the blue pedestal room after the first room in ( P-2: WAIT OF THE WORLD ).

ENVIROKILL - Enemy killed by the red substance found in the liquid tunnel in ( P-2: WAIT OF THE WORLD ). This bonus was also used in earlier versions of the game before hazard-specific environmental kill bonuses replaced it.(1)

SCRONGBONGLED - Enemy killed by the red substance found at the bottom of the elevator in the inner sanctum in ( P-2: WAIT OF THE WORLD ). Under normal circumstances no enemy should be capable of reaching the pool, as they should all have been killed to progress through the level. However, by loading an earlier checkpoint in the level after grabbing the blue skull, it is possible to un-kill enemies in the level, notably the Mindflayers, which can teleport into the substance.

SCRINDONGULODED - Enemy killed by the red substance found in the shortcut in ( P-2: WAIT OF THE WORLD )

COMPRESSED - Enemy corpse is crushed by a collapsing black hole from the Black Hole Cannon in the Developer Museum.

why are you even spawning enemies here - A unique style bonus only available in ( 5-4: LEVIATHAN ) when a spawned enemy or their corpse falls into the underwater abyss.

ROCKET RETURN - Make a Guttertank's or Defense System's rocket hit itself without riding on it.

SLIPPED - Make a Guttertank kill themselves by dodging their punch.

STRIKE! - Kill an enemy by launching a dying Mindflayer into them with the Knuckleblaster.

TRAMPLED - Make an enemy get crushed by a Minotaur.

PAWN CAPTURE - Capture a pawn piece in the chess game in the Developer Museum.

ROOK CAPTURE - Capture a rook piece in the chess game in the Developer Museum.

KNIGHT CAPTURE - Capture a knight piece in the chess game in the Developer Museum.

BISHOP CAPTURE - Capture a bishop piece in the chess game in the Developer Museum.

QUEEN CAPTURE - Capture a queen piece in the chess game in the Developer Museum.

KNIGHT PROMOTION - Promote a pawn into a knight in the chess game in the Developer Museum.

ROOK PROMOTION - Promote a pawn into a rook in the chess game in the Developer Museum.

BISHOP PROMOTION - Promote a pawn into a bishop in the chess game in the Developer Museum.

QUEEN PROMOTION - Promote a pawn into a queen in the chess game in the Developer Museum.

CASTLED - Perform a castle in the chess game in the Developer Museum.

EN PASSANT - Perform an en passant in the chess game in the Developer Museum.

ULTRAVICTORY - Win against a bot in the chess game in the Developer Museum.

WHITE VICTORY - Win as a white side in the chess game in the Developer Museum.

BLACK VICTORY - Win as a black side in the chess game in the Developer Museum.

BONGCLOUD - Perform a bongcloud opening in the chess game in the Developer Museum

FOOLS MATE - Perform a fool's mate in the chess game in the Developer Museum

and there you have it
the worst guide of the year
If you want me to add somemore combos just say it in the comments