The editorial team at sub-Q Magazine is looking for speculative interactive fiction up to 5,000 words, although 3,500 is preferred. If you can’t do the programming required to make your piece interactive, just submit your story together with a document explaining how it would work as an interactive piece. The website publishes new interactive fiction every Tuesday, and you can see examples here: https://sub-q.com/category/fiction/
Payment is 6¢ per word for prose, plus an additional 3¢ per word if interactivity is already programmed in. Reprints are considered at half rates. All submissions must contain some element of speculative fiction – science fiction, fantasy, mystery or horror – and either be, or crafted with the intent that the work will be enhanced by interactive elements.