Here is the full list of all 165 OxU achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Pass the level 0
Pass the level 5
Pass the level 1
Open level 1
Pass the level ?
Pass the level 8
Open level 8
Pass the level 2
Open level 2
Pass the level 6
Open level 6
Pass the level 7
Open level 7
Pass the level 3
Open level 3
Pass the level Z
Pass the level X
Pass the level W
Pass the level O
Open level Z
Pass the level Y
Open level Y
Open level X
Open level O
Pass the level N
Pass the level B
Pass the level A
Pass the game!
Open Final level
Pass the level 🏆
Open level 🏆
Pass the level 💡
Open level 💡
Pass the level 💧
Open level 💧
Pass the level ❖
Open level ❖
Pass the level ❄
Open level ❄
Pass the level ☘
Open level ☘
Pass the level 🞓
Destroy Companion Cube
Open level 🞓
Pass the level ☢
Open level ☢
Pass the level 🌐
Open level 🌐
Pass the level ⭗
Open level ⭗
Pass the level ⊞
Open level ⊞
Pass the level 🛇
Open level 🛇
Pass the level ★
Open level ★
Pass the level 💠
Open level 💠
Pass the level 🟎
Open level 🟎
Pass the level 💥
Open level 💥
Pass the level 💜
Open level 💜
Pass the level ⬡
Pass laser through the portal first time
Open level ⬡
Pass the level ◯
Aim the laser at the Companion Cube
Open level ◯
Pass the level 🌣
Open level 🌣
Pass the level ⬛
Open level ⬛
Pass the level △
Open level △
Pass the level ⚙
Open level ⚙
Pass the level ⦾
Open level ⦾
Pass the level 🌙
Open level 🌙
Pass the level ✓
Open level ✓
Pass the level ▩
Open level ▩
Pass the level ⬤
Open level ⬤
Pass the level \
Touch the Companion Cube
Open level \
Pass the level /
Open level /
Pass the level }
Open level }
Pass the level {
Open level {
Pass the level =
Open level =
Pass the level +
Open level +
Pass the level -
Open level -
Pass the level ]
Open level ]
Pass the level [
Open level [
Pass the level $
Open level $
Pass the level #
Open level #
Open level ?
Pass the level !
Open level !
Pass the level 9
Open level 0
Open level 9
Open level 5
Pass the level 4
Open level 4
Open level W
Pass the level V
Open level V
Pass the level U
Spend more than 10 minutes on any level
Open level U
Pass the level T
Open level T
Pass the level S
Open level S
Pass the level R
Open level R
Pass the level Q
Open level Q
Pass the level P
Rotate the floor with cross line
Open level P
Open level N
Pass the level M
Open level M
Pass the level L
Open level L
Pass the level K
Open level K
Pass the level J
Open level J
Pass the level I
Open level I
Pass the level H
Open level H
Pass the level G
Open level G
Pass the level F
Open level F
Pass the level E
Rotate the floor with T-line
Open level E
Pass the level D
Open level D
Pass the level C
Open level C
Rotate the floor with angle line
Open level B
Rotate the floor with straight line
Open level A