Pretty awesome for you first onepager! 
The only thing that is confusing for me is the panel on which one sees the tree for the first time. Panel says: "Important item in the middle of the panel: TREE", but the text introducing this panel says "But I've also got sleeping pills for her". So my eyes expect to see something that fits together with that. And doesn't.
I THINK the small thing on the top of the tree-panel suggests a sleeping injection, but as the text says "pills" and nowhere else it gets clear that he has a weapon that can send sleep "injections", that's a little bit hard to understand.
How about making the tree-panel a "standalone" panel, with no diagonal egdes and a bubble in it that says "Finally!"? Diagonals are for action (or disagreement), and in my imagination he is in no hurry anymore when the door to the tree opens, but has already defeated the AI.
And the victory over the AI happens in the panel before? The last John who makes a hand stand could rip out some cables with the free hand or do anything that makes clear he switches of the AI? Or smash it on the ground if it some kind of drone. And the text could only say "Gotcha!", as this would be enough and would not take away much space.
In the panel in which he is taking a nacho, it would be more natural to mak him look at his FINGERS and the nacho they are touching, instead of lookinh upwards.
Oh, instead of my suggestion of writing "Finally" into the tree-panel, you can put the "Target retrieved" there, and the text "The only tree grown nachos in the universe" fits much better into the panel where the nachos are visible for the first time.