Here is the full list of all 35 Smashing Spirits: Brazil's First Boxer achievements.
Complete all levels, including the bosses.
Complete all levels on hard, including the bosses.
Complete all levels on hard, including the bosses and get all secrets.
Rescue all monkeys on 3 levels.
Catch all hearts on 3 levels.
Kill all enemies on 3 levels. (on hard)
Do a 8 hits combo.
Do a 20 hits combo.
Do a 30 hits combo.
Do 3 full combos in a row.
Unleash the 4th overload level.
Kill all enemies on cave level. (on hard)
Finish forest 1st level on hard.
Finish forest 2nd level on hard.
Defeat forest's boss on hard.
Finish river 1st level on hard.
Finish river 2nd level on hard.
Defeat river's boss on hard.
Finish cave's level on hard.
Defeat cave 1st boss on hard.
Defeat cave 2nd boss on hard.
Finish forest's 1st level in less than 4 minutes. (on hard)
Finish forest's 2nd level in less than 4 minutes. (on hard)
Finish river's 1st level in less than 4 minutes. (on hard)
Finish river's 2nd level in less than 4 minutes. (on hard)
Finish cave's level in less than 6 minutes. (on hard)
Finish forest's 1st level in less than 7 minutes (killing all enemies on hard).
Finish forest's 2nd level in less than 7 minutes (killing all enemies on hard).
Finish river's 1st level in less than 9 minutes (killing all enemies on hard).
Finish river's 2nd level in less than 10 minutes (killing all enemies).
Finish cave's level in less than 17 minutes (killing all enemies on hard).
Defeat forest's boss in less than 2 minutes (on hard).
Defeat river's boss in less than 2 minutes (on hard).
Defeat cave's 1st boss in less than 3 minutes (on hard).
Defeat cave's 2nd boss in less than 90 seconds (on hard).