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