+Open Adventure is an author-approved open-source release of
+Version 2.5 with, as yet, no gameplay changes.
+Version 2.5 was essentially the same as Version II; the cave and the
+hazards therein are unchanged, and top score is still 430 points.
+There are a few more hints, especially for some of the more obscure
+puzzles. There are a few minor bugfixes and cosmetic changes. You
+can now save a game and resume it at once (formerly you had to wait a
+while first), but it now costs you a few points each time you save the
+game. Saved games are now stored in much smaller files than before.