To reiterate, we're basically operating on Valve Time now.
[Kunoichi] Game will be released on DLSite and other sites When It's Done™
[and was supposed to release by Jan/Feb, but didn't]. He's adding more to it other than just patching bugs (see below; although he also admits that he's just bad at restarting work on a product that he previously considered to be "finished").
And about that other full-length game
[the one with the blonde, as you call it] he was working on before C91: In that same blog post he made regarding the Kunoichi game, he said that he'd resume work on it only
after he finishes with the Kunoichi game, so....
Edit: Well, you're really lucky. Parsing through his recent tweets, at least there are signs of progress.
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Sensitive pictures (or whatever they're called) don't load if you're browsing without an account any more, but it's a screenshot of the other Kunoichi character from the game, complete with in-game mechanics. (Guess there's a segment where the player is in control of her now.) It's probably safe to say at this point that he
is adding in additional content.
続編というよりかは、冬コミ頒布物からの追加分になります! -> Pretty much translates as "it's not a sequel, but I'm adding additional content to the base game".