I guess tinyBuild saw how even Hamster can put their Neo Geo games on sale once in a blue moon, and have now been inspired to hold a sale of their own, their first ever on the Switch eShop IIRC. Most of their games are 20% off but beware that many have been reported to have framerate issues among other problems. Might want to do a little research before pulling the trigger on any of them.
Personally, I won't buy their stuff with the issues. That aside, stuff like party hard won't include the co-op like on PC. Kind of shitty for a Nintendo system. CEO and their Twitter dodged that question for a while. I'd always ask during AMAs. I just don't feel like they put their best foot forward.