[6] In Los Angeles in 2012, he was a finalist in Boy's U16 Singles, losing the final to Canadian Coby Iwaasa, 15–11, 15–13, after beating Mexican Erik Garcia in the semi-finals, 15–7, 7–15, 11–10.

[8] Acuña played at the 2014 International Racquetball Federation (IRF) World Junior Championships in Cali, Colombia, reaching the semi-finals of Boy's U18 Singles where he lost to Conrrado Moscoso, 5–15, 15–4, 11–3.

He was at the 2012 World Championships in Santo Domingo, Dominican Republic, where he and Ivan Villegas lost to Ecuador's Jose Daniel Alvarez and Fernando Rios, 15–14, 15–14, in the Round of 16.

The next year he played Men's Singles at the 2013 Central American Games in San José, Costa Rica, where he lost to Guatemalan Pedro Sandoval, 6–15, 15–8, 11–8.

At the 2016 World Championships in Cali, Colombia, Acuña played Men's Singles, and lost to Luis Perez of the Dominican Republic in the Round of 16, 10–15, 15–10, 11–7.

Acuña played the 2017 Pan American Championships on home soil in San José, Costa Rica, and that may have helped him reach the semi-finals for the first time, beating the USA's David Horn in the quarterfinals, 15–10, 15–12.

In doubles, he and Felipe Camacho defeated Colombians Set Cubillos and Mario Mercado, 15–4, 15–3, in the semi-finals, but lost to Mexicans Alvaro Beltran and De La Rosa, 15–9, 15–3.

In Men's Singles, he defeated Ecuador's Fernando Rios in the Round of 16, 15–14, 15–2, then in the quarterfinals he beat top seed Mexican Alejandro Landa, 6–15, 15–14, 11–7, but lost to American Charles Pratt in the semi-finals, 15–13, 11–15, 11–7.

In Men's Doubles, he and Felipe Camacho beat Argentinians Fernando Kurzbard and Shai Mazuri, 15–5, 12–15, 11–1, in the quarterfinals, but lost to Canadians Samuel Murray and Coby Iwaasa, 8–15, 15–1, 11–3, in the semi-finals.

Acuña and Camacho also played Men's Doubles at the 2019 Pan American Games in Lima, Peru, where they beat Guatemalans Edwin Galicia and Juan Salvatierra, 15–8, 15–5, in the quarterfinals, but lost to Bolivians Roland Keller and Conrrado Moscoso, 13–15, 15–12, 11–7, in the semi-finals.

At the 2022 World Championships in San Luis Potosí, Mexico, Acuñan earned a bronze medal in singles, as he reached the semi-finals with a win over Guatemalan Edwin Galicia, 8–11, 11–4, 7–11, 11–5, 11–3, in the quarterfinals, but in the semis, he lost to American Rocky Carson, 8–11, 7–11, 11–7, 12–10, 11–4.

His best finish was in Men's doubles, as he and Gabriel Garcia reached the semi-finals, where they lost to Mexicans Javier Mar and Rodrigo Montoya, 11-4, 11-7, 11-4, resulting in bronze medals for Costa Rica.