Both types of mines are spherical, a metal brown in colour, and have a yellow dot in the middle of their spherical body. Both mines stay in one spot, and will expose their yellow eye to watch Blue when he walks past, keeping a close watch on him and bringing their eye back in when he goes some distance.
There are two types of mines in Test Subject Blue: floor mines and air mines.
General game information
Both mines are indestructible, and will explode and kill Blue if Blue makes any contact with the mines. They will respawn a few seconds after destruction. Blue's proton cannon bullet, and enemies like orange enzymes, will not set Mines off. If a mine is right next to Blue's checkpoint and if he touches it while invincible, the bomb will explode and automatically respawn. Blue will still be alive.
The first type of mine introduced is the air mine, which will stay positioned in the air, watching Blue when he walks past. Air mines are the more frequent type of mine seen in Test Subject Blue. The second type of mine is the floor mine, which appear to be partly in the floor, but are really a half of mine in the ground, and not a full mine.
The floor mines are seen to be bigger in width than the air mines, with the floor mines having a bigger body and eye than the air mines. Floor mines are less seen than air mines, and will raise their head up out of the ground to watch Blue when he passes.
There is also a higher chance Blue will avoid being killed by the floor mines, since they can be easily jumped over, unlike the air mines which are placed in places Blue wold be likely to be. Mines are only placed on the floor of levels, never on any other platform in the air.
Mines make very few appearances in Test Subject Green, probably because more dangerous weapons and hazards can be used. Mines appear in Test Subject Arena, but only on the bottom floor of level eleven.
A mine appears on level four as the goal for the level. It is slightly larger than the Test Subject version, and is more detailed.