Any Planet Is Earth is a 6-page FKR/OSR space adventure game by Jim Parkin.
In a nutshell, it is to Classic Traveller what Into the Odd is to Dungeons & Dragons
It's 3$ and very good.

I don't know how to write reviews yet, this is a first.

Also I'm in the "acknowledgments" section at the end of the game so I may be biaised.

What You Get
It's six pages, landscape, four columns in small but readable courrier new. First page is all the rules for character genreration, dangerous things and combat.

Second page is a Traveller-like services "minigame" with stuff like events, mishaps, boons and benefits, as well as an abstract wealth system (petty cash, assets, debt). Being familiar with Traveller, I had very little trouble figuring it out, though it could benefit from some clearing up of both context and form (as it stands, the text feels a bit crowded).

Then you get some more setting-specific rules like interstellar travel, commerce, misjumps and advancement as well as some good examples of overloaded encounter dice to generate interesting situations, and a page of useful referee advice (keep crew debt in mind at all times!) and an example of play. Yes, an example of play in a 6 pages games, I love that. Show, don't tell.

The last two pages are maze rats like d66 tables (24 of these!) to generate sectors, planets, NPCs and situations fitting the Traveller flavour of Space-faring Sci-Fi Adventure. These are a great reason to get the book even if you don't use the system, as they are completely rules-agnostic.

How It Works
 It's basically a 2d6 saving throw system with a few bells and whistles. It assumes Free Kriegsspiel or OSR type play, with the Referee being the final arbiter and using dice only as oracles. It is rules-light and focused on "diegesis" or internal engagement. You will have to make things up, and add rules when you feel the need for them (you don't actually need extra rules).

You have three stats, Strenght, Dexterity and Sociability (Social Standing) - you only record a descriptor for a very good or very bad stat. Then you enlist in one of the spacers' branches: military, expeditionary or merchant, and you get stuff. Eventually you come out middle aged and with some skills (descriptive), some gear and maybe a rumour or other adventure hook.

Here's a guy I just rolled:

Ensign Ariel Melss (age 22, 1 term in the star navy)
Strong, Quick, VaccSuit, Handgun (reach)

Most of the time you do stuff by asking the Referee if you can do it and talking. Maybe you make a save by rolling 2d6, 7+ to succeed if you're good at it, 9+ if you're not. The chance of success is low because it is not meant to be a "skill check", but a save for when things are already messy and difficult.

One thing I love is that violence is handled without rolling dice. You get four hits, and different broad categories of weapons have guidelines for how many hits it inflicts. Initiative is simultaneous, and you just hurt each others by default in a non-clever fight. Which means you ALWAYS have to think about tactical positioning if you want to win - otherwise it's a zero-sum game, or at least you'll come out of your first fight unable to take on anyone else afterwards. There's some details like armour reducing damage and tags like (auto) granting extra damage. Simple stuff. I talked a bit about why I think this is great so I'm not going to expand too much on it, except to say the following: 

BEGIN DIGRESSION

This way of dealing with violence puts the emphasis on Combat as a Puzzle (a War puzzle)
See, when players enter combat in a heavy RNG game like B/X, the framework kinds of tells you to stop thinking in terms of problem-solving and start thinking in gambler mode: "hah, I might get that sweet natural 20 and do MAX damage!", "hah! If we fight one more round maybe we'll get lucky and they'll run away" etc. Keeping combat diceless (though I would still recommend using Traveller surprise with APIE) removes that gambling impulse - there is no being torn between the optimal strategy and the most exciting choice (randomness) because the most exciting choice becomes whatever optimal strategy you cook up. That means that you don't have a scale of values with "winning the fight by killing the foes" insidiously tucked at the top in the players' minds. Suddenly running away is as fun as shooting because it has the same level of commitment and mechanical weight. When you enter a combat with diceless, auto-hit+auto-damage, there is no real distinction between exploration mode and combat mode. It's like fighting the Troll in Zork - "swing sword at troll" doesn't sound as wise as "run past/sneak past troll" and the gameplay rewards have the same shape (more description text).

END DIGRESSION

Moving on. Comparing it again to Classic Traveller. I said in the beginning that it gives it the "ItO" treatment. In the sense that it takes all of the good exciting bits provided by the old mechanics, but strips a lot of the technical complexity, removing the barrier for entry. Misjumps are interesting, so have a table just for that purpose. Commerce and trade is interesting, so have a basic way to determine demand and surplus, tied with the abstract wealth measures, and you can have rules-light space trading adventures now. Starships are great, and streamlined. Here's a ship.

The Rake
Scoutship, 6 slots, 2 hits, 1 armor
2-hardpoints, 1-cargo, 3-range

That's it.

In Traveller, generating subsectors is fun once you figure it out and you internalize all the numbers. The UPP is all well and good but it doesn't help me if I don't remember what each number ties into. Now, here's a planet generated with APIE:

AVERNOY
Terrain: Flat
Population/Size: 1M+, 1/2g
Main Faction: Scholastics
Guild: Seers (neuroscience)
Trade Goods: Plastics (+), Biotech (-)
Crises: Tectonic Shift
Rumors: Unknown Signal

Easy! Here's the description I came up with from these tables.

"Former imperial paradise world, the verdant plains of Avernoy are dotted with glass spires inhabited by tall elfin people fascinated by the powers of the mind. Their dwindling population is split into three castes – scientists, philosophers and traders. Thinking machines handle most other jobs, from menial labour to administrative processes. Recently, major tectonic shifts have caused natural catastrophes,
putting a dent in recent efforts in fertility-focused bioengineering research. A mysterious signal has been broadcasting from the largest, abandoned moon."

Did I mention the advice is very good?

"Let a PC swindle a merchant or sincerely ply their trade in serious honesty. Let a PC one-shot a heavily-armed merc with a knife because the opportunity presented itself and the player opted to capitalize on it, perhaps at great risk." (for Referees)

"Regardless of direction, the galaxy is yours. You dictate what happens, what interests you, and where you go. Follow leads, but make your own, too. If you want it, go find it. Fight for it. Whatever it is. Work as a crew and a family. Your debt is always shared." (for Players)

Some Issues
It's not perfect. As I mentioned, the text feels a bit cramped - it would benefit from more spacious layout, maybe a cleaner font. Some bits are difficult to parse if you have no prior knowledge of Traveller and would be more accessible with more in-depth explanations, especially trade rules and character generation. In a future second or revised edition (which I'm waiting for excitedly since Jim mentioned he was doing something like that!), I'd drop the four columns landscape, or figure out a way to have it less packed, like Maze Rats somehow did (how, I do not know). There's also some oddities when it comes to how stats can change during your terms, even though you're supposed not to record stats beyond descriptors in chargen (it's not a big deal to me but it could lead to confusion).

House Rules
I've mostly run it with Shadowrun as a setting, as well as a few solitaire delves, and picking up bits and pieces for my other games (like Classic Traveller). Here's a thing though:

Additional Protection, be it from Piecemeal Armor, combinations of Heavy Armor and Shield, or any sort of technological or supernatural protections, should grant extra Hits once you reach "Armor 2". That is, it makes sense to be immune to 1-Harm attacks like fists, and I can get behind Heavy Armor protecting you from knives. But once you get into 2-Harm stuff like guns, it should always stay dangerous. Yet there are cases where you have diegetic protections in addition to Heavy Armor. That's when you give PCs extra Hits. For example, if I was wearing Battle Dress (heavy armor for -2 to hits taken) AND using a Ballistic Shield AND wearing a force field belt, instead of reducing hits by 4, making me essentially invulnerable, I would add two hits to my character, for 6 Hits instead of 4.
Hopefully Jim can write it in a way that is clear and concise in the new edition!

Maybe add psionics? I like psionics.

Voilà. Go get it, it's like, three bucks.