Update. So, I bought
this thing. It works... mostly. Choplifter worked for like 5 seconds before it stopped. But the other games worked at first. But now, the screen flickers green every once in a while. There was some stuff on the contacts (despite being "brand new"), so I'm guessing that was it. It might also be that these Master System games are ancient... Genesis games are working fine {well.. the ones that still work, do anyway...)
I bought 4 games at a local store (well, two in one). Everyone has Outrun, unsurprisingly, but I didn't buy it. The arcade port that's included in Outrun 2 on the Xbox is more than enough.
Hang On/Astro Warrior
Choplifter (CIB!)
Kenseiden
Choplifter isn't working for me. I opened it up and it looks almost pristine. The game just might not like this aftermarket adapter made in China. The box is definitely original. It even has a Game Catalog from 1986. The manual is mostly in good shape (though not in the near perfect shape the Catalog is, indicating the manual got usage). There's a scorebook log on the 11th page. Someone named Tony liked this game enough to record some of his scores in 1988. High score is 355900. I assume this is a high score.
Hang-On is like a crummy version of Mach Rider. You die in one hit, but it's incredibly difficult to avoid other riders. Mach Rider also played better and had a great song. The Genesis 6-Pak has Super Hang-On. It's MUCH better. Easier to play, and it looks better.
Astro Warrior is fun. I turned on the turbo on my controller so I can just hold the fire button and shoot endlessly without getting tired. I only played up to the first boss. Level was easy, only died because I tried to kill enemies. No one shoots at you so you really just need to avoid contact... but then the boss was like an intro to bullet hell games. There is some kind of checkpoint system, because when I died the third time both times, the boss battle started. There is no HUD in the game, so you can't tell how any lives you have, how many points you scored, and how far you've made it in the level. There's a nice upgrade system, like most good top down shooters. An item floats down the middle of the screen, if you pick it up, you get a stronger weapon. It's fun. I don't know what's up with the sudden difficulty spike, though.
Kenseiden is hard. Your character can take a lot of hits... that's good because you're going to get hit a LOT whether you want to or not. Some enemies are suuuuuper cheap. There are these armadillo looking things that crawl on the ground. They move slowly, but if they get a certain distance, they turn on the burners and hit you before you can react. There's another enemy that jumps around like a spider monkey and if they get on the same level as you, they're a pain to deal with. Most enemies home in on you. If they're on a different level, they can't get to you, but they'll follow you until there's a hole they can drop down and get you. Enemies are super annoying. The recoil from every hit is worse. I watched a video review on this, and the YTuber mentioned the recoil and how if you get hit on a platform where there's a pit, you will fall off because you are locked into the animation for an entire second. I love the visual style, though. The extreior shots are really nice. Second level has a red moon, which I thought was pretty cool. Kenseiden is also the one game of the 3 that seems to work every time I plug it in, despite the game sticker with the name being in the worst condition.