Flame Zapper Kotsujin (PC-98)

Flame Zapper Kotsujin is an excellent game. I'm starting the review off with that statement, just because it's hard to know exactly where to start in singing this game's praises.
The most obvious things when you start playing are the graphics and sound, both of which are of a very high quality. The graphics are excellently drawn, making good use of the PC98's high resolution, as well as using some nice pallettes.
The music is excellent. That's all there is to say about it. It's just really good, catchy shooting game music.
Great presentation can't really standup on its own without a good game behind it, though. But like the opening sentence of this review says, Flame Zapper Kotsujin is an excellent game. I'd go as far as to say it's the best of all the PC98 games I've played (though admittedly, this isn't many. At a guess, I'd say about 20-ish) (And yes, I've played the Touhou games. They're just a bit better than mediocre, to be honest.).
You've probably already worked out that it's a shooting game, and it was made by a team called CO2-PRO, who made a few other PC98 shooters, including the Gradius fangame GARUDIUS 95 and the okay-but-nothing-special Last Breaker. Their body of work, as well as the quality of it suggests that CO2-PRO were big fans of the genre. And this love especially shows in FZK.
It plays fast, with lots of enemies and bullets constantly onscereen. There are three weapons to choose from, a red spread gun that's kind of weak and useless, blue bendy homing lasers, and a very powerful yellow gun that fires straight ahead. You also have the usual bullet-cancelling bombs, but in a nice touch, the bombs look different depending on which weapon you have at the time: red bombs release a bunch of toaplan-esque skull-shaped explosions up the screen, blue bombs summon four extra ships to shoot a giant screen-filling array of lasers, and the most spectacular bombs are the yellows, which summon a giant celestial hand to fill the screen with bolts of lightning.
The game also has a number of different scoring methods, ranging from the obvious (finish a stage without dying or using any bombs to add multipliers to your end of stage bonuses) to the obscure (at least three different techniques of getting big points from the Eighting/Raizing reminiscent medals that enemies often drop).
The only negative criticism I can give this game is that it is a little bit too easy. I'm not even very good at shooting games, and I can get pretty far into the final stage on a single credit. That's on the default settings, though, and you can always turn the difficulty up.
If you're at all interested in shooting games, I very much recommend you seek out and play Flame Zapper Kotsujin.

Yumemi Mystery Mansion (Mega CD)

I remember when the Mega CD first came out in Europe, this game was previewed a lot in magazines. I assume it got so much attention because of the prerendered CG graphics, and the fact that there wasn't anything else like it on the SEGA consoles at that time. Since then it seems to have been forgotten by history. I'd even forgotten about it until recently, when I played it for the first time.
It's an adventure game set in a mansion, that you entered following your sister, who in turn was following a butterfly. You wander about the mansion, seeing it all in first person perspective, and although everything is prerendered, it still moves pretty smoothly, and though the graphics are low-res and very grainy, that only adds to the atmosphere. Atmosphere is by far the game's strongest point. Even though there are no enemies, and there are only (as far as I can tell) two ways to get game over, the game still manages to be creepy just by the strength of the atmosphere it creates, and the bizarre premise in general. The only other characters you meet in the mansion are talking blue butterflies, who are the souls of people trapped in the mansion by its owner, the unseen malefactor referred to as The Hunter. Your objective is to find your sister and get out of the mansion before midnight, at which point you and your sister will join the other residents as butterflies, trapped in the mansion forever.
As there are no enemies in the game, the only things obstructing your escape are the various puzzles in the mansion. Most of the puzzles being of the "find the item/key and use in the right place", made even worse by the fact that you're often given no indication as to where the items will be, and on top of that, some items can be seen from the start of the game, but can only be picked up later in the game when they're actually needed, with no indication that this is the case. I'm slightly ashamed to say that I actually had to resort to consulting gameFAQs for the final puzzle.
Despite all the faults this game has, I still say it's worth playing for the creepy dreamlike atmosphere, especially if you're interested in horror in videogames. It's only an hour or so long, so it's not going to waste too much of your time. The fact that it's so short, coupled with the general lack of gameplay and the fancy graphics does make it seem more like a tech demo than an actual game. It probably would have been more fondly remembered had it been a pack-in with the console than a full price stand alone purchase.
(This game is also known as "Mansion of Hidden Souls")