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