Not a bad Doom clone at all. The weapons are quite varied and besides that, you can upgrade weapons to make them even more varied. For example, the iconic weapon of Doom II, the Super Shotgun, is also available in this game, and you can upgrade the Super Shotgun from double barrel to quad barrel. Levels differ in texture and theme. My favourite levels were the ones belonging to the chapter set in an industrial environment. There is a boss battle at the end of each chapter and they are quite easy to fight on normal difficulty. But I distinguish the last boss from the others. Unless you pay attention to ammunition management, it is completely by chance that you fight and win against this boss consisting of 5 phases. I'm quite satisfied with this little Doom clone and I'll try the 2nd game when it's on sale.