"HAPPY BIRTHDAY GRIMACE" agressively drinks the accursed shake and then starts imploding
...That whole meme aside (which comes from how unfortunate it seems that some people actually had got poisoned by the shake, hence the "drink and die" format), which is funny to think it overshadowed the event/game, the fact they released a bona-fide Game Boy Color game that even has an error screen if played on stock GB hardware and everything is quite cool.
I did not hear about the poisoning thing, I did see some TikToks about the drink, they portrayed it as a horror thing, maybe they were connected?
I think that's the reason why that even became a meme in the first place...