Really, no joke. There's more fantastical stuff that can warp reality... as in, Doraemon had a beak that when worn allowed someone to turn anything they said into reality among a funkaton of other things to solve the problem in one go. When Nobita meets Doraemon the first thing he asks is to use the Everywhere Door to get everyone out of there and the sequel they do consider using time travel to prevent the whole mess. Interestingly, the games avoid this by having Doraemon be one of the bad guys.
Even disregarding those, Doraemon has weapons like a gun that can blow up tanks and a ray gun that can melt concrete buildings, so yeah you have firepower well above what horror survivals feel like giving you normally XD. Not to mention, Nobita himself is actually kind of pretty hardcore when push comes to shove. If you've ever watched any of the Doraemon movies he'll cry and freak out for like a few seconds and then jump to save the world from time travelling criminals, alien overlords, mythological abominations, etc. Not to mention he has gunplay that would make Revolver Ocelot proud.
Nobita's Resident Evil honestly is a pretty fascinating thing, aside the outlandish premise it's actually pretty clever in design, well at least for its day. Nowadays horror games in RPG Maker and horror spins on kid's media is much more common.