I did play Ruina, 2 playthroughs actually and about 15 hours of ざくざくアクターズ
For Ruina I am really surprised it didn't get a translation by now, it's one of the most famous free game in japan for good reason, the game play like a P&P CRPG with roll dices, you can choose your protagonist gender and birth, if s/he is the son/daughter of a noble training to be a knight, an abbandoned child raised by a thief, etc... this isn't just a cosmetic choice since the way people react to your protagonist change heavily based on your birth, each of these lineages have their own unique quests too.
You go through dungeons, each levels having their own sets of traps, enemies/bosses, hidden items and puzzles to solve, go back to the city to talk the colorful npcs, meet new allies and progress their storyline...
There is a lot that could be said about Ruina, it's definitely not a game I can talk about here so maybe in another place one day.

As for ざくざくアクターズ I'll just say what I liked about it first, there is a lot of cute art and the characters are fun, the humor isn't bad either. Gameplay-wise you use 4 characters but can freely change between the 8 you have in your party, it allows a lot more freedom you'd think.

But the game just didn't manage to grab me in anyways so I had to quit, the "gameplay loop" aka go through a dungeon go back to the hub, see some story event, go to another dungeon felt really dull in particular since the dungeons themselves are not designed in any ways, the enemy mobs just feel randomly placed rather than being part of an actual setting, seeking treasures and the like felt unrewarding, I was just dreading actually playing the game passed a certain point.
I may give it another try one day but that won't be soon.

Except for Ryuuou, that is excellent by the way but I didn't read any LN lately.

The last books I read in japanese were mostly SF, the 2 volumes of 裏世界ピクニック that is a mix of the famous SF novel Roadside Picnic aka STALKER and japanese urban legends about 2 girls finding themselves exploring the "backside" a world filled with monstrosities and where every step can be your last, I really enjoyed what I read.

I also read 最後にして最初のアイドル, a compilation of SF short stories by a new writer, all the stories are extremely hard SF full of infodump, they go very far but it was pretty good for a newcomer. The first story literally started as a Love Live fanfiction about Nico pretty literally becoming the greatest idol in the universe.

But otherwise I've been lazy due to Rance and work being very busy recently though this isn't an excuse

VIP games are something that are a bit too large to elaborate in retrospring but to keep it short they are created by very active community in 2(5)ch
VIP creates a lot of stuff, web manga, web novels (some pretty famous), eroge, games..., it's a culture on its own
Among these my interest right now is mostly in VIPRPG, the Moshimo series to be precise since there are other community among VIPRPG like Monarpg, google it you probably already saw some of their games and iconic ASCII characters

Now the Moshimo series is a shared universe created by VIP using the generic characters found in rpg maker, it started with a simple 2 minutes game created by an anon named "If the hero was the strongest" about the protagonist of rpg maker 2000 Alex going to defeat the Maou, Alex is seemingly invincible and effortlessly manage to do so.
It's incredibly dumb and honestly not very funny but somehow it caught on and spanned an entire shared universe made of hundreds of characters and thousand of games, some being 10 seconds long and other 100 hours long
As you can see it's really not something I can talk about here.

I'll try to write something more elaborated on the subject soon

it's not like I do it all the time.
the way to avoid burning out is to never force yourself, personally I try to mix and match and just do whatever I feel like at the moment, I can spend an entire free day lazing around while I can also spend hours trying random vip games, playing a game, reading a book, watching a movie... the one thing I never do is keep a schedule though especially since my job demand a lot of focus and ask for me to be a "serious adult", I'd rather keep it easy at home

The reason I like looking for obscure things is simply curiosity by the way, I really hate the idea that I could be missing something good hidden somewhere