Perspective Practice Preview - Robot doodles

TL;DR: Feedback requested, if you see any problems with my picture, no matter how nitpicky, please share!

I wasn't planning to upload anything for a long time, but since it's just been one day... I decided to make an exception, after yesterday's perspective practice which was meant to be my last upload for 3 months...
This is how my next day starts, well... besides 2 hours spent making brushes   (which were not used in this image anyways, I just had to make myself a basic hard round and soft round brush in paintstorm,  I somehow still hadn't... Now I have, and they are glorious I remember spending literal days in krita trying to find the perfect settings for a soft brush; a lot of nightmare fuel was created but ultimately no brush that I was completely satisfied with, so when I found out about paintstorm after dicking around on youtube I switched over in a flash, and I'm so glad I did this program is a riot!)

So because it went so much better than expected, on first try (beginners luck for sure I refuse to believe it's anything else!!) I decided to make an exception and share it, because for my first true attempt at drawing not just two objects, but full fledged characters and not just one but two standing next to each other (I mean... I hope...) beginners luck or not, that seems to have gone pretty well. The characters themselves are just doodles, randomly generated, I just threw together the first basic forms that came to my mind, and did the expression thing with the head pieces this is also sort of my first serious attempt to keep a consistent light source across more than one object, and one of my first attempts to draw cast shadows. I'm not gonna lie, I have an ulterior motive for uploading this...

I need feedback, somehow I have this feeling that this is looking much better to me than it really should, I'm pretty sure I'm making at least several huge mistakes in these sketches, but I cannot for the life of me see them. For some inexplicable reason, I do not hate this work, please help me hate it. it doesn't feel right to like something I've drawn, so please point out all my horrible mistakes, you get brownie points if you make me cry! so go extra hard on me, show no mercy!! make me bleed!! (yes I want you to nitpick at every little detail that you notice is wrong, any mistake you can point out will help me greatly)

It is bugging the living shit out of me that I cannot see what is wrong with this picture. Help me see my mistakes!! I feel blind!

Edit: After consulting with the cool guy who finally helped me understand perspective (that dude ) and a few others I now understand these things, I missed a highlight, on the right robot's head there should be a highlight, I didn't draw it because it is just one plane but since it is meant to be metallic there would be a highlight there, also the cast shadows do not follow the perspective, it looks like they are on a slant instead of flat to the floor, and the robot on the left side has out of perspective feet, while every part of the feet individually is fairly correctly drawn in perspective, the legs as a unit are not in perspective while this is fantastic for a first try on drawing something a bit more complex than a box, and maintaining consistent lighting between many objects, I've got some ways to go.