I adore the Fantastic Voyage and other works where the setting, the backdrop is a realistic or fantastic depiction of a living thing (See also Cells at Work which is sort of both?) I also absolutely love metroidvania games, with their mix of platforming, puzzle solving, coming back to old areas with new powers and the occasional ludicrous sequence break. So when I saw Bio-Gun, I immediately jumped on it. Bio-Gun is currently still just in demo, with the completed game expected out later this year, but even so, there's a lot to love. The Story, the gameplay, and the aesthetics are all superb, so let's go over them all one by one.
The story of Bio-Gun is that in the near future, a new disease, the "dooper virus" has managed to elude all attempts by medical science to quash it, and it threatens to kill all dogs on the planet if not brought under control soon. One scientist - DocX - desperate to save his own dog, puts his own "blood, sweat, and tears with the Dooper Virus itself - and a small extract of bacon to add a little irony for good luck - to create the ultimate cure: Project Bio-Gun. The plot is at once complete earnest and totally absurd, and I am one hundred percent here for it. The actual plot thus far has seen Bek, the titular Bio-Gun injected into a Dog's womb, fought several nasty viruses, saved several dog-like cells, raced the ghost of a sperm, and found its way to the bladder and caused the dog to pee all over its exam table, and more. All of these things are hilarious and make me just want to see what's going to happen next. The writing is hilarious and the voice acting is spot on. Everyone is playing their characters absolutely straight and it makes the jokes just hit harder.
Now, the aesthetics. You can see an example of this yourself, but to put it into words, the art designs feels very reminiscent of Hollow Night except aiming for vitality and colors instead of death and monochrome. Hero Bek is a tiny pig man in a haz-mat suit, save stations are hazard scrub showers, native cells look like cat people in hoods, dogs, and other strange cartoon characters, all of whom have a distinct look and yet all still feel part of the bizarre world that is the inside of a dog. You start the game in the dog's reproductive organs, and move from there to the bladder and other organs and muscles around. Each area has its own color and theme, so it's hard to get lost - especially with the map - and the enemies and allies that you meet have easily identifiable shapes; a villager is immediately identified by its hood, the dog-like cells you must rescue look immediately doglike, enemies all look like viruses and bacteria and bugs. There's a lot of visual information but it's all there with the intention of keeping track of everything going on on screen.
Now then, the gameplay. First off, it's a metroidvania that starts you off with a dash move. An aid dash move, even, so you know it's respecting your time and skills. You also start with a healing ability and a radiation meter that acts as your MP, and which recharges from drops and attacking enemies with your gun. Yes, as expected from a title called Bio-Gun, you have a gun. Well, no, you have several guns, each of which serves a different function - and some of which consume your radiation to fire - and furthermore every gun can be aimed with either the left or right stick (the right stick takes priority so you can fire left while walking right, for example) and this quasi- twin stick shooting leads to some amazing boss fights. You also have the opportunity to level yourself up and buy equipment through the use of Globs - the game's equivalent of money - giving you an auto-firing turret gun, longer air time, or other boosts to your character. You can only have one upgrade active at a time, and they can be quite expensive, so blast lots of virii and collect all the globs you can.
Of course, there's more to Bio-Gun than just run and gun. There's plenty of puzzles and platforming challenges, like a race with the second fastest sperm that wants one more chance to prove itself, or the quest to rescue doglike cells that have wandered off into every part of the host body, or the quest to find and reattach all the nerve strands in the bladder to help your dog host relieve herself and prevent an infection (and make a mess of the lab table in the process). Especially fun are rooms with enzymes. So far, these come in two flavors: radioactive, which fills and turbocharges your radiation meter for a short while, and explosive, which destroy blockages and almost always involve navigating Bek from one side of a room to another despite enemies and hazards to explode at just the right spot. These start out fairly straightforward but later ones have required dodging alternating death traps that will send you back to the start of the course and aggressive enemies.
Lastly, boss fights. These have so far all been some form of horrific virus monster, but each one has had its own look and feel and been a blast to play against. Each one has its own strategies against you and a way to counter or negate those strategies if you pay attention. Especially of note is that one boss who you fight in an arena it has prepared before time, repeatedly tries to reinforce itself with additional viruses as you deal it damage, but you can actually get ahead of this strategy by destroying the capsules holding these reinforcements before the boss can unleash them.
All that said, would I recommend going out and buying Bio-gun immediately? Well it's not out yet, so no. But definitely try the demo, and if you like it, wish list the full game and buy it on release. I know I will be.