He tried to kill him. After he fires the Kamehameha that blows up Freeza, in the manga at least, there's a shot of just his sad face. He truly did not want to kill Freeza. He wanted to spare him, but Freeza left him no choice, and Goku had to kill him.
Goku defeated Frieza during the climactic battle of Dragon Ball Z's “Frieza Saga,” one which began after Frieza decided to hunt down the Dragon Balls of Planet Namek in order to use their magic to become immortal.
In the anime Goku looks more mad than anything else after Freeza attempted to kill him after he had just lent him some of his energy. However in the manga (feat. my thumb!), it appears to be more sadness than anger that couples Goku's disappointment.
3 Frieza. Goku doesn't try to spare Frieza out of mercy or kindness, but pity. Goku wants Frieza to know that he's so pathetic, he isn't even worth the effort to kill. Frieza was right all along.
Frieza: Killed by Future Trunks. He chopped him in half with his sword, sliced him to pieces, and shot an energy blast that reduced him to dust in midair (In alternate future, he was killed by Goku).
This shows that Frieza is still an evil psychopath despite becoming friendlier but he is not as cruel as his first appearance on Namek.
Freeza hates Goku more than anyone or anything else. Because until Goku fought him on Namek, Freeza never came across anyone who could challenge him in an outright fight. Any and every fighter that went against him, Freeza would kill him with his eyes closed. But not Goku.
Yes, Frieza was afraid of Saiyans. He was afraid of their growth in power rather than the communal growth. The movie “Dragon Ball Z: Bardock – The Father of Goku” coveys the same.
9 NEVER WILL BEAT: Beerus
Unfortunately, the difference in power between Beerus and Frieza is immense, meaning that there's simply no way that Frieza can overthrow this permanent thorn in his side.
It's funny to see Goku forgiving Frieza despite all he did while over at the MHA sub people can't forgive a hero for being mean to his kid.
Firstly, it was to repay the debt he owed him from back on Namek when Goku gave Frieza a bit of energy so he would live from his injury after he accidentally cut himself in half.
Frieza returns to his cocoon in Hell after being killed by Goku, though this time in his organic body. A manga extra feature reveals that he is joined in Earth's Hell by his subordinates Sorbet and Shisami.
In the early days of Dragon Ball, there existed a being strong enough to beat the God of Destruction Lord Beerus, but Goku accidentally killed him.
Cell. With the notable distinction of actually killing Goku as opposed to beating him, Cell's defeat of Goku was as swift as his own inevitable loss against Goku's enraged son Gohan.
By the end of the Tournament of Power, despite still being openly as evil and selfish as ever, Frieza has come to respect Goku and his allies, and willingly celebrates with them for a little bit as well after being revived by Whis.
1) Goku's fear of needles
His constant screaming and flailing required more than half a dozen people to hold him down. Eventually, Chi Chi comes in and, through her prodding at Goku's expense, reveals the Earth's hero is indeed afraid of needles.
10 Vegeta's Grudge Against Frieza Only Grows Stronger Over Time. Most Saiyans have reason to resent Frieza, but Vegeta is a special circumstance. Frieza is responsible for the extinction of the majority of the Saiyan race, including the destruction of Planet Vegeta and the murder of Vegeta's father.
Freeza hates Goku more than anyone or anything else. Because until Goku fought him on Namek, Freeza never came across anyone who could challenge him in an outright fight. Any and every fighter that went against him, Freeza would kill him with his eyes closed.
Jiren. Jiren is the strongest member of the Pride Troopers and is Toppo's closest and most trusted friend. He is also the strongest fighter of the 11th Universe and is Goku's main rival in the Tournament of Power.
Zamasu. His hatred for Goku was so massive and deep that it transcended time itself.
Within the Dragon Ball world, the term "Monkey" for a Saiyan would be considered racist, because it is a slur that is meant to demean the Saiyan race due to a physical characteristic. So when Frieza calls them "Stupid Monkies" he is actually using a racial slur.
The only beings Freiza has any respect for are his father, King Cold, and his siblings. They are freakishly strong like he is and share enough history that he has developed the kind of respect for them that a child is forced to adopt when their family is strict and abusive.
Zeno is the most powerful being in the Dragon Ball franchise. He has the power to erase an entire universe in an instant. A power he is happy to display during the Tournament of Power. Something which also happens to catch the attention of Frieza.
Goku forgave him. That's literally it. Frieza's personality didn't change, he didn't repent for his past actions, his debatably-good deeds during Super were motivated solely and entirely by self-interest.