Here is the full list of all 30 Star Crossed achievements worth 1,000 gamerscore.
Maintain maximum star speed for 30 consecutive seconds.
Slay 1,000 enemies
Slay 5,000 enemies
Slay 10,000 enemies
Use every Ulimate in any game mode
Play as every combination of characters in any game mode
Complete Story Mode for the first time
Complete Story Mode with The Weapon and The Outlaw
Complete Story Mode with The Weapon and The Hero
Complete Story Mode with The Idol and The Weapon
Complete Story Mode with The Princess and The Weapon
Complete Story Mode with The Hero and The Outlaw
Complete Story Mode with The Idol and The Outlaw
Complete Story Mode with The Princess and The Outlaw
Complete Story Mode with The Hero and The Idol
Complete Story Mode with The Hero and The Princess
Complete Story Mode with The Princess and The Idol
Complete Story Mode with all character combinations
Get S Rank in Story Mode
Use 5 Ultimates in one round of Arcade mode
Starboost 10,000 times
Get an S-Rank in Arcade Mode
Last 5 stages in Arcade Mode
Last 10 stages in Arcade Mode
Exceed a score of 10,000 in Arcade Mode
Get damaged 100 times in any mode
Defeat the Witch without either player taking damage.
Defeat the Twins without either player taking damage.
Defeat the Scientist without either player taking damage.
Defeat The Sorceress without either player taking damage.