Humor is good,like it.Have some Undertale vibes,reminded me about old game called Lemmings.
Good concept,but after zombies appearing, game becomes a little bit harsh.Levels too small and it hard to juggle robots sometimes.Also lava dont pause while you move a robot. So last levels a very pain in a ass, if you ask me) Good idea will be to add counter to show how many robots you can lose. Or even better idea - let a player survive until every robot is destroyed.But its you choice)
Good job,i maybe use some of your ideas in my next projects.Difinitely give you credit for that)