Shark Side of the Moon is the story of ... oh geez. To its credit: the premise and progression of events are not that difficult to follow. There is perhaps also some level of self-awareness that they are making a B-movie, and the viewer has some knowledge of what they are getting into with this, so in a manner of thinking, some fault lands on you for watching this and expecting something better. Unlike some other movies in this tier such as: Santa's Summer House, I don't sense they are trying to trick people that it's something it isn't. That being said: they are trying to ride the Sharknado phenomenon of "ironic" viewers.
Remember Street Sharks? The "sharks" in this "movie" are rather similar to that. They are bipedal humanoids. The movie didn't need to have sharks involved since the titular shark element has to be able to: walk on land, speak, and be able to use tools. They wanted "shark" involved in hopes of gaining some hipster audience. We see through this. We see what you did there.
So, back in Soviet Times, the Russians secretly made Street Sharks as a type of super soldier but couldn't control them, and some lab people tried to make an escape on a fueled space shuttle that just so happened to be just outside of the Street Shark lab, but wouldn't you know it: some Street Sharks got onto the shuttle before it could take off, and that happened. It doesn't really make sense that a space launch site would be right next to a biology lab, and it would have to be pretty far away from anything anyway since, a lot of clearance would be needed for the rocket blast, and you can't just drive off a space shuttle, since there needs to be someone in a control center to start the launch, and that the Soviet Union never used space shuttles since that was a short lived proprietary US technology, and the Soviet Union only used Soyuz rockets, and space launches take lengthy preparation and just "winging" one means drifting into vacant space if you survive the launch at all, but it is a movie about militant Russian Street Sharks, so what am I expecting?
Fast forward to present day, or maybe the future, where we pick up on a seemingly unrelated story about some American astronauts. I say maybe the future because: their spacecraft is very roomy and has consistent Earth like artificial gravity that maintains even when other systems are damaged. It also has some very futuristic furnishings. These are gamer chairs they are using. The kind you could get from Walmart or some store like that. Their "coms" earpieces are Apple earbuds. Now, we can imagine they are listening to true crime podcasts during the movie shoot.
So, somehow, when our modern and / or future day space heroes arrive on the moon, they not only found that some street sharks had survived on the moon but had built a large generational city there. Supposedly, there were abundant raw materials on the moon (as well as lava), and the crashed 80s shuttle had tools to help them get started? And look, I'm not a space expert. I don't know what technically and actually is or could be on the moon. However, I want you to consider: do you really want to die on a hill defending the "scientific accuracy" of THIS movie? Do you really think these guys did their homework on this?
Also, the one human who lived to pilot the shuttle somehow survived and managed to salvage enough in his own right to survive alone on the moon these 40 and/or 60 years later. Somehow, the sharks left some stuff for him, including rations and breathing gear, and he has a "daughter"; a human looking person with some "shark" attributes. What I was figuring at first: somehow, after a fateful night with a street shark, a basket is at his door and... well, no, not that. Apparently, this was a street shark that was born with human appearance traits, and she was rejected for this, and had to be raised by the surviving Russian guy. You would think that being created to conquer and having a whole culture based on returning to Earth and fighting for "shark" kind, would have her and any other human looking anomaly street sharks in specialized training for intelligence and reconnaissance, but they just let her get raised by that one human they didn't kill.
The way they pretend they are walking on the moon looks ridiculous because: it looks like they were in a limited green screen space, and I suppose this goes to the ship, and all indoor settings on the moon somehow having full gravity. It is only "the moon" when they are "out of doors" on lunar sand. The acting ranges from competent for some characters such as the aging cosmonaut, cringy and badly cadenced in the case of some American ship crew members, and sometimes just goes into the "I'm acting" cadence that comes with the kind of no-budget "indie" movies that were shot in cheap hotels.