These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Word of God confirms that the character of Non-Human is a guy in a mech suit. The Action 52 Owns remake for Non-Human builds on this.
And what about the fellow from Sombreros? Some thieves steal a bunch of hats in such a rush that they drop them all over the place. This prompts our hero to pick up a gun, walk down the middle of a road into oncoming traffic, shoot a bunch of innocent cars (which explode) for getting in his way, and try to shoot the unarmed culprits dead while they try to frantically escape his line of sight, all to get said hats back.
Then there's the company itself. Some people say they are a waste of time, others say they are unsung heroes of the industry for inspiring other game companies to spur themselves to greater heights.
Considering Action 52 was made by only 4 people in a span of 2 months, 3 of which had about a week of training before hand (and one who had none), there's enough evidence to support the "underdog" interpretation of the game.
The theme from Cheetahmen. No one is sure how it happened, especially when every other song on the cartridge ranges from "mediocre" to "ear rape," but it did. Additionally, it got many, many remixes on the Japanese video site Nico Nico Douga.
The theme for Ooze on the Genesis version, which was done by Nu Romantic Productions, who were responsible for Toejam And Earl's and Kid Chameleon's soundtrack.
The remake of the Illuminator theme from "Action 52 OWNS" turns an other wise crummy theme into something really awesome. Hear for yourselves
The remake of Non-Human has awesome stage music as well as boss music. The original music only appears at the end section of the game.
To quote a comment on YouTube, "The only good thing about Action 52 is the music."
Bile Fascination: Everyone knows how horrible Action 52 is. Despite this, years later, players are still delving into the games in this title, using emulators to beat the ones that are unbeatable (or to actually play the ones that normally crash immediately upon selection), and even posting tips and tricks for the games on YouTube.
Demonic Spiders: Most games include at least one type of it, and frequently more. Some deserve a special mention.
Hairdryers in Fuzz Power, which shoot nearly impossible-to-dodge stuff at player at random. Made worse by the fact that main character has only a melee attack.
Tiny red spheres in Micro Mike can spawn in random parts of the screen and then home in on the player. Since it's only possible to shoot forward, getting hit is guaranteed when these spawn above, below or behind the player.
Starting from stage 3, many enemies in Bleeps 'n Blips have incredible speed and homing ability, allowing them to hit the player in a fraction of a second. It doesn't help that your character can only shoot in the direction it's moving (and not diagonally).
Almost every enemy in the 5th level of Cheetahmen has these traits. They either move so fast and lock on to the player that there's only 0.2 seconds maximum to shoot them down, or they're just too low to hit (Apollo can't duck).
Pretty much any enemy in Haunted Halls, due to their random spawning, Goddamned Bats behavior, and the fact that you can't crouch. The worst one may be the "Skull of Doom".
The literal Goddamned Bats in the later levels of Illuminator. They home in on you at high speed, are nearly impossible to hit before they hit you, and you're a One-Hit-Point Wonder to boot.
Droplets in Ooze. To defeat them just wait for them to fall. Slowly. Many times in some stages.
Good Bad Bugs: Glitches to get around the glitches. There are many of them, some of which have to be used to complete the level.
In Manchester, you can't pass a certain point because of flames being in a way. However, you can fall through the floor and walk past a huge stack of note blocks.
These are also found in Underground. While walking into the walls is sort of amusing, the ability to fire through the walls (properly utilized) takes the game all the way to "genuine fun" territory.
In Dedant, the player can only shoot upwards. If enemies reach the bottom row, death is almost guaranteed unless you hide at the edges of the screen where no enemy or their projectiles (not even the homing ones) can get you.
Aries (in the 2nd level) and Hercules can jump in mid-air by pressing jump just after attacking. This trick carried over into Cheetahmen 2.
In many games, Bottomless Pits actually make the character reappear at the upper side of the screen. In Lollipops, attacking in mid-air while falling will reset the falling height and cause the character to reappear in the sky, allowing you to skip a few sections of the map.
In several games, the number of enemies spawning can be reduced by firing a lot of projectiles or not killing current enemies on screen. Often it's also possible to scroll enemies off the screen which is extremely useful in Haunted Halls which stops the enemies spawning behind from getting you.
In Chill Out, when jumping constantly, edges of the screen can be used to get up without using ladders. This helps to get up and shoot the enemies relatively safely.
Certain actions in Fuzz Power make the main character unable to do its attack, but in return, make him invulnerable.
In Non-Human you can jump and stand on the mouths of the green Elton John heads without dying. It is possible to bypass the entire level this way.
Hilarious in Hindsight: The Action Gamemaster was a failed system, but nowadays, the Retro Duo Portable System can play both NES and SNES games with today's technology. And the Retron Console can even play Genesis games as well. If only Action 52 was a decent game and the company would've waited until today ...
Guide Dang It: Mostly on account of laziness on the part of the developers. A few of the games become surprisingly playable once you know some horribly uninituitive trick to them. For example, Streemerz requires the player to step off the side (and it has to be the correct side) of the top platform in order to progress to the next level. Meong could be considered an extreme case, as learning to play it seems to be almost impossible without help.
Similarly, a pillar in the first level of Bubble Gum Rosy can only be cleared by standing so you're just barely hanging onto the edge of the previous platform, then jumping, with pixel-perfect timing that convinced many people it was impossible.
Also, the guide was often flat out wrong on what games were on the cartridge, which takes this trope about as far as it can go.
Memetic Mutation: The Cheetahmen games (especially part II, which was in its own cartridge) are the subject of several parodies and tributes on the Japanese video site Nico Nico Douga.
Misattributed Song: The music from Silver Sword, French Baker, Fuzz Power, Streemerz, Time Warp Tickers and Ninja As(s)ault were actually composed by Ed Bogas. Ed's work is used without approval, and uncredited.
Nightmare Retardant: In Non Human, after fighting waves of weird-looking mutant horrors, you then start facing off hungry cyclopean heads. They look like adorable smiling orange dog/cat/hamster heads, which takes away any creepy factor.
The Giant Enemy Crab/Bug thing in the Hard mode of Non-Human. It has two heads as the weakpoints, the top head fires out a bouncy energy ball while the bottom fires out one that travels across the floor, then moves up when under you. Both of these attacks hurt a lot, and then there's the fact that the boss is constantly advancing towards you and limiting your space. Your solution is to shoot the heads to push him back, easier said than done because the crab can use his claws to guard either the top or bottom one!
That One Level: For the curious, if a single game on the cartridge were to be chosen as the worst of the lot, it would probably be safe to go with Micro Mike. As for individual levels themselves, there are quite a few candidates:
Levels 3 and up in Bleeps and Blips
Level 1 and 2 in Billy Bob.
Level five of Cheetahmen.
They Just Didn't Care: Apart from the obvious signs, many of the descriptions in the manual range from mentioning things that aren't in the final product to clearly being for completely different games.
Parts of the manual are in Engrish. Usually, that's acceptable. Not for this, since the game was supposedly made in the United States.
It's possible that the manual was written by one of the foreign investors of the company, or that the team of 4 who programmed the game were simply completely out of it by the time the manual was written
When you consider, however, that the entire game was made by a team of 4 guys who had only 2 weeks of training before hand, and that all 52 games were made in a span of 3 months, it comes off less as a lack of care and more as a tragic tale of being against the odds.
Unfortunate Character Design: In the third screen of the NES Cheetahmen's intro sequence, one of the trio's tails is sticking between his legs in a way that looks more than a little phallic. The illusion is made even worse by the fact that we only see the Cheetahman from about thigh-up in that screen.