Ginga no Sannin (銀河の三人), 12/15/1987, developed by Pax Softnica, published by Nintendo

This is a Famicom port of a 1985 computer game called Earth Fighter Rayieza. From what I have read (and can see on video playthroughs), the Famicom version is more or less a complete remake rather than just a straight port.
The setting is the year 2300, where an invading race known as the Garm have destroyed all the space colonies and taken over all human habitations except for Earth — Earth is protected by a barrier but it’s only a matter of time before the Garm breach it. The main character and his companion Blue are entrusted with the Rayieza space mechs in order to defeat the Garm.

First you have to respond to a distress call on the moon.

This is the main space map. You choose a place to visit and then move towards it. You can move a number of “steps” equal to the number of boosters you’ve picked up, although moving more than 2 will cause HP damage. So if a place is 34 distance, and you have one booster, you’ll have to do 17 two-step jumps to get there, and each one can have a random encounter. This becomes rather tedious as the game goes on because it doesn’t have the exploration feeling of a normal overworld map, you’re just pressing A over and over again and doing fights.
On the moon we do the first dungeon:

Here you move around through a maze. There are no encounters in this one but there are in other dungeons. We find a girl in a capsule and bring her back to Earth to recover, then go out into space again. The main goal of this first section is to destroy the three Garm ships (the green things on the map above) and then the Garm base. But you have to prepare for that by building up money and levels and buying better equipment.
Levelling up only increases your max HP, and when Remi (the girl) joins you early in the game, she will also increase her EP and learn new support moves. The only other way to increase your power is to buy items. There are two types of weapons. The first is the basic beam attack which attacks all monsters and can be used infinitely. The second are your missiles, which are limited. You can shoot as many missiles as you have. (You also get promoted in rank after a certain number of battles but I don’t believe this has any effect).
There are hidden level limits based on how far you are in the game, and 40 is the highest possible.
Basically you want to get the best stuff you can from the first space map area (the Mega Ion and S-Missiles) for both the main character and Blue, and that should be enough to take out the three Garm ships.

Fights are like this — you can see the enemies and their HP. Your beam attacks hit all enemies but the more enemies there are, the less damage it does. The missiles work the same way but do more damage.

When you fight the ships, you first have to close into their range before you can shoot them with missiles and such, so you need a fair amount of HP and healing items.
You can visit the various planets as well but there’s really no point at the moment. Once the three Garm ships are destroyed, you find out that an escape capsule went to Uranus, and we still can’t damage the main Garm base.

I got a game over in the Uranus dungeon (which sends you back to your last password place with half your money taken but everything else intact), and this is where I stopped.
I think that the game has some interesting ideas, but the travel and battling feels like a slog because it’s so repetitive. I’ve also read the the game suffers from increasingly severe balance issues; you can only hold 9 heal items and level 40 is the maximum. It seems like later in the game you just have to run from nearly every fight in the dungeons to avoid getting a game over, and levelling up gives you only a slight advantage.
The story has some interesting twists at the end, but there are long periods of no story development at all, just going to different dungeons for fetch quest items.

In the end while this has some interesting aspects to the gameplay and might be worth a try, it’s probably not worth playing to the end.
Personally when I played it it was super fun… and the battle’s music is godly. I understand the game is a bit repetitive, that depend if you like map the dungeon continue the game. If you don’t really like the game it’s okay.
I would put it in the middle rank of games from this era — it’s not an example of the crap tier stuff that’s bad even for its time, but it’s not one of the top games either. I think it’s playable to the end if you are willing to put up with the creaky parts of the system.