Same as @mr-matt never-ending zoom-out, I think this is because you try to keep all the slimes inside the viewport... but one slime is falling to infinity and the stage is locked on the bottom-left of the screen. I want to say that of all the linux games I've tried yours is the only one I managed to start. So bonus point for that ;) The graphics are nice, the music is decent. Congratulation on your submission.
Happens repeatedly when I kill a slime. Just gets smaller and smaller