Here is the full list of all 17 The Ninja Saviors: Return of the Warriors achievements.
Defeat the boss of Stage 1: Giant!
Defeat the boss of Stage 2: Chain Sawyer!
Defeat the boss of Stage 3: Phantom Gecko!
Defeat the boss of Stage 4: Silverman!
Defeat the boss of Stage 5: Jubei!
Defeat the boss of Stage 6: Phobos and Deimos!
Defeat the boss of Stage 7: Zelos!
Defeat the boss of the Final Stage: Banglar!
Clear the game with Kunoichi without using a continue.
Clear the game with Kamaitachi without using a continue.
Clear the game with Ninja without using a continue.
Clear the game with Yaksha without using a continue.
Clear the game with Raiden without using a continue.
Clear the game with all characters without using a continue.
Clear the game in multi player without using a continue.
Clear the game with a total time of 3000 seconds or lower.
Clear the game with a total time of 2500 seconds or lower.