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