Depressive symptoms are prevalent among young adults, with cognitive theories suggesting that impaired cognitive control contributes to sustained negative mood and depressive symptoms. This study investigated the feasibility and efficacy of a remotely-applied, tablet-based cognitive control video game, Legends of Hoa'manu (LoH), for reducing depressive symptoms in subclinical adults. A randomized controlled trial (NCT05447091) was conducted with 173 participants (mean age 33 ± 11.6 years; 75.1 % female) exhibiting at least a minimal level of depressive symptoms (PHQ-8 ≥ 5). Participants were randomized into three groups: high-dose experimental game (HD_EG; N = 58), low-dose experimental game (LD_EG; N = 61), and high-dose control game (HD_CG; N = 54), with interventions spanning three weeks. The intervention demonstrated high feasibility and adherence (69.5-76.5 % of sessions completed) without direct study contact. Overall depressive symptoms (BDI-II total score) improved across all groups, with a significant main effect of time, but no significant group differences. Still, group differences were found for the cognitive-affective BDI-II subscale, where the HD_EG group showed the largest reduction (4.5 points vs. 2.3 and 2.1 in the LD_EG and HD_CG, respectively). These improvements were maintained at 3-week and 3-month follow-ups. Secondary outcomes, including anxiety and rumination, also improved across all groups. Overall cognitive control performance did not differ between groups; however, significant improvements in inhibitory control emerged exclusively in the HD_EG group. The results highlight the feasibility of this novel, cost-effective, and remotely-applied cognitive control-based intervention. These findings underscore the potential of LoH as a scalable solution for addressing depressive symptoms in subclinical populations.