Lucky indeed there! Just reading comments here, I figured on my own that getting this could be interesting and tricky, got it with 274 points. No rat king visible, nor the purple slimes near the start, but chanced upon the rat king soon enough, able to avoid stepping on a rat.
Best scores probably would be getting the gnome, but that needs quite some luck around the dragon (or keeping retrying clearing around the dragon early until getting there).
Good little game :)