Boss Trials is a play mode in Battle Bears -1. A trial is unlocked for each boss as they are encountered and defeated in their respective stages during the Campaign for Oliver and Riggs. Wil does not have any accessable Boss Trials. By default they are all set to medium difficulty. Nonetheless, Boss Trials are harder than usual levels.
- Mecha-Bearzerker - Oliver's Campaign Stage 2 (can be played by Riggs when completed as Oliver).
- Tentacleese - Riggs' Campaign Stage 3 (can be played by Oliver when completed as Riggs).
- Spaceboss - Oliver's Campiagn Stage 3 (Oliver only).
- Roboticus - Riggs Campaign Stage 2 (cut).
- Under Construction - Wil's Campaign (unknown).
- The Boss Trials icon features a silhouette of Tentacleese and the Mecha-Bearzerker.