build me a simple fps game

I need somebody who can make a A very simple and basic firstPerson shooter game which has multiple levels. The first level shall have 3 rooms and the rooms shall be connected through a door. The person shall only be allowed to use the open the door once all the targets have been destroyed. The 2nd level shall have 4 rooms,3rd level shall have 5 rooms,4the lv shall have 6 rooms and 5th level shall have 7rooms. All these levels shall be different scenes where the scenes shall be linked with the build scene. The person shall be allotted 30 seconds per room in all the scenes. The targets can be simply a capsule (or any gameobjects).The gun shall have a crosshair too.