Thanks for your comment! As agxgames pointed out, in this version (version 9 for Windows and Linux, version 8 for Mac) there is a bit of a bug with when the opponent screen shows up. It should appear only when the player defeats the opponent (the opponent runs out of health), but that's not what happens in version 9 (or 8 for Mac). One of our teammates is currently working on the fix. If you find the version number is different, the rest of this comment may be out of date. What we seemed to determine in our tests is that the screen shows up when the player is defeated (loses all their health) and occasionally at other times (perhaps when the player and opponent health are both low)? Thankfully, there are a few workarounds because of keys I put in for debugging. Pressing semicolon will open or close the opponent selection screen, from which you can proceed as normal (player health won't reset upon choosing an opponent, so if you were at half health before, you will start the next fight at half health; player health is reset by something other than the thing that opens the screen). There are also 3 keys to directly transition to each opponent (with the caveat that you can't select an opponent that is the same as who you (the player) are), but I'll leave those as an easter egg unless you really want to know :P