I have one question. Object that is controled by player has a collider that is trigger and when it collides with other object i want them to become "a part of him", like they are glued together, and to go wherever he is going.
Is that possible?
Just parent it.
other.transform.parent = transform;
In case the object had any other movement code, you might want to disable it. For example remove any rigidbodies (or possibly make them kinematic but I don't know by heart if it carries over well to parented objects).