Anyone is free to stream the Lore Finder demo or make video of it for YouTube, including monetized, explicit permission can be found here: https://kitsunegames.com/press/sheet.php?p=lore%20finder#monetize
This depends on if we meet our 'Girlfriend mode' stretch goal or not. We're confident we will meet that goal before the end of the campaign, in which case we'll aim for the game to last around 10 hours for an average gamer who doesn't explore all of the game. We also intend to add New Game+ which would extend the life of the game even further. A completionist playthrough of the game, including girlfriend mode, could probably take upwards of 15-20 hours at that point.
Players on Linux can of course install the game via the itch.io app or the Steam launcher. For DRM free (on itch) we intend to have a bin installer using MojoSetup. This installer will use MonoKickstart to bundle all the dependencies the game needs, and so should run on a variety of different distros. We've used the same strategy with success with our previous game, MidBoss, which has even been run on OpenBSD. For more information on MojoSetup and MojoKickstart please refer to the FNA wiki at https://github.com/FNA-XNA/FNA/wiki/3:-Distributing-FNA-Games#gnulinux
Making the gun shoot horizontally was relatively easy to implement. Making it shoot diagonally is technically much more complex. We'll investigate adding a diagonal shooting option to the full game, but we can't make any promises for reasons of design and balance.