Well, "you go to someone's house and it turns out everyone is dead and there's a monster in the basement" feels a bit random. It's not exactly the most riveting premise.
Instead (and this is obviously beyond the scope of what would be achievable during this game jam), what if the game was split into two days: one where you actually get to visit Frank and Laura and talk to them while they're alive, and one where you come back to find them dead? I think that would be much more interesting.
Right now, Frank and Laura are some random people we know nothing about; finding their corpses really doesn't shock the player or affect them in any way. Having them be characters which we've previously spoken to would make their deaths much more impactful.
Additionally, it's just more interesting storytelling. You could make Frank and Laura be a bit weird and eccentric themselves, making Mack doubt whether they're really keeping something supernatural in their basement, or if they're just delusional. You could create ambiguity as to whether they were killed by the entity or if they killed themselves (though it's the "anomalous entity" jam, so maybe there'd be no point in including such a red herring).
It would also be nice to have a bit more justification for Mack breaking in. As-is, he just tries the door once, they don't answer, and he immediately decides that his next best course of action is to smash their window with a brick. It's a bit extreme, even for someone so desperate; "he really wants this scoop" cannot be used to justify everything. I feel like it would make more sense if he noticed the carnage inside and entered in order to investigate (I mean, one of the bodies is by the window and should be clearly visible).
Of course, this is just me spit-balling random ideas. You don't need to listen to my advice - I've never made an adventure game. I just feel like the current premise is a bit random and hasty. There really isn't any build-up to the horror, which makes it fall flat in my eyes. No offence.
Anyway, hope that helped! Good luck with all your future work.