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.