Here is the full list of all 32 Inline achievements.
1000 lines cleared
Reach max level 10
Reach 600 score in 50 moves
Play 20 normal games
Completed 3 lines in 9 moves
Find every easter egg
Push an AI to crash the game
Try to access debug features and meet their guardian
Use the Gameboy command in the console and enjoy tastelessly emulated graphics from the past
Lose after using 5 skips in a row
Reached more than 9000 score in total
Reach streak of 5
Play Custom Mode
50 lines cleared in one session
20 skips used
Beat your own highscore 3 times
Reach level 5 without skips
Reach combo of 3
Reach a combo of 4
Reach level 5
Reach streak of 3
Drop a shape outside of the grid
50 shapes placed
Lose with no lines cleared
Skip when no more skips are left
Spin one shape 20 times
Rotate a shape that will not change the orientation
Skip a single block
Repeatedly press ESC at the main menu to display the game with inversed colors
Find the option hidden in the options menu, and enjoy them "soft-body physics"
Type RAIN at the main menu and let the rain work its magic
Click and hold main menu title for 5 seconds