Of course it's all just a bit of fun, but I would never consider a game released in the last year or so for best game ever. It's only in the fullness of time that you can reflect on how good a game actually is I feel. Super Mario World is of course twice as good as Undertale and 2000000 times more significant.
NB. Sonic the Hedgehog 2 is a better game than Pokémon Red/Blue too, but I'll let it slide as I like both games a lot.







