Here is the full list of all 18 Hyperspace Invaders II: Pixel Edition achievements.
LEVEL 00 CLEAR!
LEVEL 04 CLEAR!
LEVEL 01 CLEAR!
LEVEL 02 CLEAR!
LEVEL 03 CLEAR!
LEVEL 05 CLEAR!
LEVEL 06 CLEAR!
LEVEL 07 CLEAR!
LEVEL 08 CLEAR!
LEVEL 09 CLEAR!
RETRO MODE CLEARED!
SOULREAPER: 100M score!
SOULGRINDER: 1 MILLION SOULS!
5K Souls in 1 game.
10K Souls in 1 game.
20K Souls in 1 game.
COMBO MASTER: 5K Combo!
LEVEL 11 CLEAR!