Where to put the period?

Here’s the latest screenshot from Siboot:

This shows the player’s input: Caroonycorck (the player) goes to Koopie’s house. All that’s left it do is confirm the command, in effect saying, “Yes, this is what I want to do, so do it!” In the text-based version of Storytron, this was done with a period button stuck, quite naturally, at the end of the sentence. But these pictorial sentences are two-dimensional in structure, so there’s no “natural” point that can serve as the end of the sentence. So I need a new approach. 

The obvious solution is a pushbutton that indicates “execute this command”. It could be as simple and recognizable as an “OK” button. But an OK button in English seems out of place in the Siboot world. I do have a glyph for approval, but it also serves as the verb “agree to”:

agree

Perhaps I could strip it of color to indicate that it is a sentence particle rather than a conventional word, like so:

execute command

But then where would I place it? It certainly can’t be forced into the sentence structure; it would have to be somewhere else. The lower left corner would be a good place; my sentence structures make it almost impossible for any word to appear there. Yes, I think I’ll run with that.

Problem solved; that’s the value of these design diaries.