*SPOILER SB-129 ENDING*
In order to get the secret ending, you have to get the corrupted ending. There you will find a secret code in the endscreen (5cwftDiZ9ZY). This code is a YouTube video. Type the following link into your browser:
In this video you will see 3 highlighted “Cans”. In game you will have to click on all 3 “Cans”. (You will hear a sound if you clicked on the right one)
When you clicked on all 3 “Cans” and collected all 7 items go to the end to the game. There you will be teleported to the secret ending.
If you need any further help let me know!