It is cute, short, simple, and a nice nostalgic trip back down memory lane, even if these are new yet forgettable memories. I appreciate how much the developer was able to capture the N64 look and feel, and also the Banjo-Kazooie composer Grant Kirkhope cameo (he has one of the only voiced lines in the game; he didn't work on the soundtrack). I think with some time, money, and a bigger team I could see Siactro making an honest to goodness great modern N64 game, but as it stands this feels a little too simple and shallow for my tastes.
There's no fatalities, no headshots... Macbat64 is honest good fun in the same way you enjoyed roaming about with a bear and a bird in his backpack once upon a time. But £5 for an hour of gameplay? That part would be left up for you to decide!