After a bit more than a year since the previous release, here is the newest demo : https://mknight.itch.io/remote-weapon-gunfencer
It mosly added some polish and features to the pre-existing 3 stages that were playable in the previous build. The exact list of changes is pretty big given the time gap bewteen the two releases so here's a summarized list of new things you can find in this build :

-Visibility improvements to the main game, with darker backgrounds and slower camera movements to help focus on the action and the foreground elements. Point counts when destroying enemies and picking up medals are also toggleable and off by default.
-Addition of a test room feature, which is an endless stage with harmless enemies. It can be used to test the controls and most mechanics in the game.
-Reorganization of the main and option menus, with their own submenus.
-New color schemes for the GunFencer
-Recap screen at the end of each stage
-Special Bonuses triggered by performing specific actions on some enemy types
-Bosses summon helper enemies in a dynamic way (the faster you destroy them, the more spawn)
-Some enemy waves and boss patterns adjustments
-Life cap at 3 (but all midbosses spawn a 1UP)
-New animated opening video
-Improved Sword slash effects
-Some enemies can fire destroyable bullets
-VSync ON and OFF options (when launching the game). The game logic should also be framerate-independant but I haven't tested it on a 144Hz monitor to confirm.
-Analog inputs for shot/sword/bomb
-One new outfit for Emily, the game's heroine
-Additional visuals in the VN-style tutorial segment to illustrate the topics discussed

[Note : The Mac version has not been tested on an actual machine, so there is no guarantee it will work as intended]