Return of the spider, probably not the return said spider would have wanted though haha. Initially it's a very striking image, good composition and beautifully painted, the lighting is rather moody also, I like how you shifted from the pretty blue sky and midday setting, this afternoon lighting really sets a more dramatic scene.
I love the robot ripping the spider face off, rather brutal, and the robots stance really gives the impression he's the dominant one, no struggling, simply standing onto top of the spider and ripping its face off, nice. You have really began to improve your backgrounds as well, as before they were quite sterile compared to the drama going on in the foreground now I see you have added a lot of ground detail, crashed cars, traffic, wreaked buildings that stretch off into the distance, very impressive. Whilst I have noticed that the spider has green lights and the robot has red to separate them I still think that at first glance both machines tend to almost blur into one, looking at the image further you can tell them apart but due to their similarities in both colour and design they merge too easily, perhaps if one had more insignia, bands of colour, camo? Look at modern aircraft or tanks, a lot will have distinctive patterns or bands of colour or different parts will be a different tone. The lighting, as said before, is rather moody though the highlights on the machines in certain areas could have been improved, you have some beautiful highlights going on but on some small surfaces directly in the suns path you could have some really saturated specular highlights, but then again I can see that it seems like a rather foggy day and that would diffuse the lighting a lot. The helicopter in to the left seems a bit out of place, due to its motion blur its hard to point out, the other helicopter is fine but maybe adding some form of explosion where its firing would add both more drama to the scene, and also add some more colour.
The large tower blocks behind the machines are a good touch, they are just the right tone and colour so not to merge with the fighting machines but work well as a backdrop, nice and simple rather than having a highly detailed wreaked building or just the cityscape.
I think this is my favourite image of yours so far, probably due to the colours and lighting working well with the images subject matter, everything moulds perfectly.
Again your painting technique is spot on and its improving with every image, working more with lighting, particularly messing with stronger highlights, bounced light and colour, using these you could in future images separate 2 or more elements within an image such as this making it easier for the viewer to instantly tell the elements apart.
Brilliant job, all these robot paintings you do really makes me want to create my own robot battle image haha.