I've been playing as a robot for quite a while now, and I've noticed a few things (probably already pointed out, but I'd like to give some suggestions)
First off is the obvious size difference. Most levels are generated for humans, and thus the robots have a tough time fitting into certain paths (Underground caves are the biggest offender for this). I'm wondering if this was an intentional balance choice, since Robots don't get affected by cold/heat? I've used Bat scrolls to get out of those situations but I don't think I should be forced to as it makes it tedious and forces me to keep the bat scrolls on an active slot. Maybe the bots can crouch when near a tight space, or maybe double tap down to make then crouch to human height and double tap up to get them back to standard height?
The other issue is that using a bat scroll while a robot you are more likely to get stuck in a ceiling when turning back, especially when in the Underground caves where things are cramped or jutting out (which is where you need it the most
Hope this feedback helps (great game by the way.. I'm totally hooked!)