What else have they done? Can't say I've heard of them
Anything else similar to Death Mark?
Death Mark appears to be something new for them.
It has a few similarities in terms of look to Stranger of Sword City, but Death Mark appears to be an adventure game, while up until now they have done pretty much only old-school Wizardry-inspired dungeon crawlers.
To the beginning:
Experience Inc. is a company formed by former staff of one of the companies that did Wizardry games for Japan. It's a bit strange, but long after the series was dead in the West (and Sir-Tech was gone), it remained popular in Japan, enough that a number of Japanese-only titles were made.
So, Experience Inc. comes from this background, and pretty much all they've done so far is old-school dungeon crawlers, inspired by Wizardry (a classic Western RPG series). But, in order to make them commercially viable (especially on consoles), their titles use anime aesthetics.
A fun fact: they started out as a PC-only developer. In Japan! Yes, these guys were so "hardcore" Wizardy fans, their first series of games was PC-only, where many of the Japanese Wizardry fan base was.
So, it's a peculiar case: there's a big contrast between their games and mechanics, and the look of the games. All their games use a very old-school formula, inspired by a classic Western RPG series, yet their look tries to be "accessible" to Japanese gamers, in order to try to be commercially viable.
Their games include: Demon Gaze, Stranger of Sword City, Students of Round, Ray Gigant, New Tokyo Legacy, and more.
Not all of them have been released on Steam.
These are the ones currently available:
And, of course:
If you want to give them a try, Stranger of Sword City is a great starting point, especially since it's frequently on sale: