Heres my advice, learn lightmapping
Better, make the rooms more realistically smaller, place more than 5 entities in one room, spread those entities out more, as in don't put 4 of the 5 entities you have in that picture near or on the same wall, that unbalances the room and makes one side look blander than the other. like you did. not really much more i can say except, thats a pretty bland and uninteresting screen shot, the point of taking a screen shot is to take interesting shots, not bland "Heres this room, there are enemy's shooting at me. wow." dont take this the wrong way, you have potential and you have the will to want to make games, just, try harder, don't rush the creation, the only thing that comes of a rushed game, is that no one but YOU *the designer of the game* will ever play it. if you want people to actually download and review your game, then i suggest spending more than 1 day making it.
You'll Know When You See It.

Death has no end