@Shitotaku
Fortunately or unfortunately, in the eroge, if you're only into school romance, you will face anywhere about 320 - 500 most frequently used kanji. And you can always use a dictionary for the weird one.
But trust me, in the eroge though, most are kana, unless you happen to pick a really weird one. But don't hold me to that since I didn't play many to begin with, just cute, school romance juice ones
I'm in a worse situation as I still cannot memorize my first 50 basics one >.<
It's not too hard to learn Japanese just to play eroge according to some people, since they are just basically common writing and conversation.