Gun Godz video guide to all triangles
There are 52 triangles in the 16 levels. They unlock bonus levels and the gold paint for the weapons.
48 triangles are obtained by acing the levels: 100% kills, 100% items and a completion time under the required time. These conditions have to be cleared at the same time to validate 3 triangles for a level.
Additionally, 4 secrets triangles are hidden in levels, behind walls:
1-3 Guard Quarters in the shower
2-2 Wastewater directly opposite the exit room
3-3 Wine Heaven on the left wall of the final room
4-2 Lobby on the right side of the square room without pillars
A level’s secret triangle has to be obtained at the same time as the other 3 triangles to validate all 4 triangles
100% video run of all individual levels (including speedrun and secret triangles) on this link.