Just played through Yume, Mokomoko erm Komomo, and 1/3 of Mare's route.
The Japanese contained in this game isn't that high in difficulty, quite simple actually. A junior high schooler, or even someone in primary (I mean a local) would have no issues with this. Someone who has passed 2級 of 日本語能力試験 would have absolutely no problems going through this game. I haven't touched the language in almost 4 years and was able to go through it smoothly with a handy dictionary.
With that said, just wanted to point out that the translation for the original game (not EH) has many (translational) mistakes... Oh well -_-;.
I can see why the original group did not want to translate EH if they got tired of the original title. The original title has a lot of content and would take quite a while to translate line by line alone. EH is no different, with Yume's route being just as long as one route from the original.
Yume's route goes through the life of the couple after her release from the hospital. I don't want to spoil anything, so will just say that the route dives deeper into their relationship, explores what happens to other characters, and pretty much arrives to how Mare becomes their child including the difficulty/complications of being pregnant with Yume's condition.
Komomo's route explores the difficulty of having Komomo call 洋 by his first name... Blah blah, nothing really important storywise happens but I like Komomo so had fun going through this light-hearted route. It contains the same humour and atmosphere from the original (i.e. almost same scene as "the princess hold" happens again, was quite funny though it was a different type of hold, she becomes resistant from last time )
Mare's route... Yeah I stopped after 1/3, it was as disappointing as Mare's from the original.
This certainly is a fandisc with the exception of Yume's route.
I would translate it if it didn't have so much content. Usually takes me around a minute per sentence which will end up being a 2+ year translation project because I have school/work.