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