Scoring Basics
As you collect medals, your item rank will increase. Each time you go up 1 rank, the medals you collect will increase in value. If you let a medal fly off the screen or you get hit, your item rank will reset. Getting hit with a bomb in stock uses it as an autoshield. The bomb serves as a Bonus Cash In that turns any bullets and enemies destroyed into high value medals that autocollect to you even when shooting.
The basic way to score is to shoot enemies, then let go of fire to collect medals they leave behind. If you start shooting again before they all get to you though, they will dim a little, stop tracking and continue to fall. These dimmed medals do not give you the current rank bonus if you autocollect them after that point but will if you manually pick them up. If you do this AGAIN before they get to you, they will turn red and will slowly fall to the bottom, regardless of whether or not you are shooting and picking them up does not give you any current rank bonus points. When you play you will notice arrows that pop up on the sides of the screen, there are not indicators of where enemies are coming from, but are indicators that there are metals offscreen that are falling to the bottom. Be wary of these warning arrows and you'll save yourself some heartbreak. Unlike what you've been told before by a particular someone, DO NOT KEEP YOUR FINGER ON THE TRIGGER ROOKIE. Gotta get used to letting go at times. There are hidden ground medals for you to uncover and collect as well, their point value being your current medal count x 1000 (x2 if you are on A rank).
When it comes to boss fights, scoring is a little different. The medal count will slowly deplete and any medals that come from bullet cancels and destroying a part are always autocollected to you. Destroying a part/the boss will net you the target's value x your medal count. Any bullets on screen when killing a boss turn into free falling point pickups that contribute to your bomb meter and give you points based on your current item rank.
Controls
The controls for the game are very basic, and you have the option of adjusting them in the keyconfig exe if need be. shift-z-x = a-b-c is default on keyboard so I will go by that. The a button is simply to Focus via Touhou. This will slow your ship's movement and show the hitbox in the center of your ship. In the main menu this button will lead to replays. The b button is your shot, which varies depending on whether or not you are currently Focused. This button will start a game in the main menu. The c button is for your bomb, and is the cancel button to go back to the main menu from the ship select or replay screens.
EDIT I'M AN IDIOT PLEASE READ: THE C KEY BY DEFAULT IS YOUR RESET BUTTON, HOLD IT FOR A FEW SECONDS TO RESET BACK TO THE MAIN MENU. VERY IMPORTANT TIDBIT THAT I HAVE FAILED TO CLARIFY MANY TIMES, USE THIS.
The Ships
As important a choice as it would be in any shmup, this game offers some interesting variety. The ships as follows, showing from left to right Type A to Type F:






Type A:
"Akin of Judgespear" This is the focused shot fast speed ship, featuring napalm explosive subshot akin to the Judgespear. There is a bit of finesse required with this ship because of the lingering napalm effect leading one to have to ease off the trigger even longer to make sure all the medals are sucked in properly. It also doesn't cover the screen in bullets like the other ships could, and have to plan accordingly so you don't get assaulted from an offside. What it lacks in screen control, it easily makes up for in great speed and high damage. Because of moments where speedkilling enemies brings out more popcorns, Type A kills stuff faster than the other ships along with Type E. This is A scoring man's ship as it is capable of some of the highest scoring potential, and in some ways better than E which needs to stop firing for an obnoxious amount of time because of that ship's destructive subshot. Unfocused shot spreads out the Napalm subshot a little bit, Focused shot makes them converge on one point.
Type B:
"Balance Poster Ship" This is the "balance" ship of Kaikan and would probably be considered "The Ryu" as it is a good ship all around with no serious weakness. It's main claim to fame is the decent speed and wide shot properties of the ship. It's amazing for what it is because unfocused, it is a screen-covering wide shot that will destroy any popcorn instantly. When focused, all of the shots move forward, meaning that for stage portions you have a ship that can tackle any popcorn dilemma while being able to focus it's shot against bigger enemies and bosses. It isn't quite as strong as Type A or E, but the fact this ship serves as a mix of both worlds of screen control all while retaining GOOD damage AND the fact that it's subshot will also cease quickly after halting shot, means that it can survive stage portions, quickly pickup medals, and get the speedkills it needs against bigger enemies for extra popcorns. This is my highest recommendation of a ship and should serve as a role model for the others. This ship is seriously solid and can do wonderful things if you learn the game's ins and outs.
Type C:
"Complex Alternative Route" This is a fairly strange ship that seems to cater for those that want something different from the other ships. By this I mean the fact that unfocused and focused shots feel like handling 2 different weapons and because of this ship's lack of damage requires it to follow a unique route for score completely different from the rest of the ships. It appears to falter early on, but picks up momentum and can actually catch up later on scorewise. Obviously as it reads homing, unfocused shot has a disc sub that homes in on enemies. Focused shot will make a target reticle appear a fixed distance from the ship that cannot be moved once it appears. This reticle will serve as the target that your sub will land precisely when shooting, letting the ship attack in a precision manner. Because of this, it is required by the player to have some prefound knowledge of the game to effectively use this effect. The usefulness of the ship is put to question with the existence of ships that can cover the entire screen immediately like B, D, or F, but there are SOME redeeming qualities to this ship, I'll leave them to you to figure that out

Type D
"Devastation Fire" This ship probably has the most "badass" feel to it the moment you get the first powerup and start shooting. This is a slower ship but thankfully it is not handicapped much because of it's awesome subshot, fire pillars that will surround on both sides of the ship. With unfocused shot, the pillars will go in a 180 degree angle behind the ship before returning forwards; With focused shot, the pillars will move backwards at a slower pace, then stop at 90 degrees before returning forwards. All pillars disappear instantly if you let go of shot. You will get used to Focusing a lot so you can make use of the slower moving pillars. With this ship's ability to cover the screen in complete fire mayhem, it can decimate stage portions without much trouble, but the bigger enemies will prove to be an issue when the pillars are not always hitting. Type D is a good fun and very unique ship that effectively captures what this game is about when properly tapping the shot for quick pillars that incinerate mobs of popcorn in one motion.
Type E (Unlocked by clearing the game, continues allowed)
"Evil Cousin of A" Similar in playstyle to Type A, but a little bit faster and a much more destructive subshot. This thing is the strongest and fastest ship overall, but at the cost of some brutal scoring problems since it's subshot is TOO destructive. This leads to having to stop shooting for even longer to ensure you don't miss medals. Difficulty with scoring sort of evens out this thing's insane power. Focused and unfocused shot do not seem to do anything differently as far as I can tell, which would be a unique flaw with this ship. I would highly suggest using this if you are trying to unlock Type F and you don't care about your score as much.
Type F(Unlocked by 1cc'ing the game, no continues allowed)
"Furious Balls" This thing is as close to a Juggernaut as the game will let it get, as it is the slowest ship and has a subshot that will make you piss your pants in disbelief. Unfocused shot unleashes a hellstorm of BALLS that spin all around your ship and generally turn the screen into a white disgusting mess. Focused shot will freeze the BALLS and let them shoot in a fixed direction. You can change the fixed position of the BALLS by releasing and quickly repressing the Focus button. The initial reaction may be that this ship is gloriously broken, but when you take a further look at it, there are some weaknesses that should be known. Outside of stage portions, the lack of control on the BALLS leads to some issues in boss fights, making it insanely hard to get the bullet cancels you need. The BALLS will block shots as they are out, but there is a huge warning for those that play this ship: they WILL shrink if you do not bring them back to the ship. They can be destroyed overtime and once this happens, you lose them and are subsequently powered down a little. You have to learn to keep things under control with this ship, or you'll look and see that you have no more BALLS.
MEDAL LOCATIONS
Thanks to Jaimers and Beatsgo for helping me out with this.
Stage 1:







Stage 2







Stage 3







Stage 4







Stage 5







VIDEOS
One video here for something to start with if you want a general gist of what scoring looks like:
Emuser - Type D 1 Billion w/Personal Comments Annotations
BUGS
There is one pretty pesky bug I just discovered, it involves replays. DO NOT. REPEAT, DO NOT quit Kaikan without first ending the replay! The reason for this is because for some reason the game shuts down in whatever state was recorded in the replay's run, meaning you could run one of your first replays, quit during it, and your high score displayed from that time and Type E and F will be locked. You could run a more recent replay and repeat this process to get them back, but it is still annoying since I haven't found a way for it to bring back your true high score if you do the bug by mistake. Always exit the replay and go back to the main menu before quitting the game to avoid this.
WHERE TO DOWNLOAD
You can download the game through the author's webpage: https://zakichi.ojaru.jp/kaikan.html
Thanks to Sikraiken for the link, I hadn't had any luck finding it earlier.
Producer's name is Zakichi, copyrighted by Kigekiyahonpo(sp?)