People who joke about Pokémon being "kid friendly dogfighting" would have a goldmine of jokes if Drill Dozer ever defied the odds and became popular through a reboot/remake. The game's literally about gang wars and police corruption, but like Pokémon it never treats those dark themes as actually dark and just expects you to accept it as part of the universe.
A small part of me wonders if DD's plot and overall aesthetic was designed as a response to, or even a scathing satire of, the "growing up with the audience" trend of the time that Spyro, Sonic, Bomberman, e.t.c. were doing - basically showing you don't have to abandon the cute factor or cartoonish semi-violent mayhem to fit in more intense storylines. Wouldn't be the first time Game Freak were spiteful towards the blue blur - GF's earlier game Pulseman was intentionally designed to be as anime as possible in response to Sonic's Western cartoon aesthetic.