I've just updated the demo; this might be the final update until release. Here are the key features, changes, and fixes you can expect:
New Features:
Mini Bosses: Now, apart from the sporadic appearance of boss levels, each level has a mini boss waiting for you to spawn on the last Mana Pump; plan accordingly!
Level Up: When you finish each level, you'll use Mana Gems to level up different stats. The Mana Gems are formed by collecting Mana during the level and filling the Mana bar. In the beginning, you'll only be able to fill up to two Mana Gems.

Changes:
Mana Cost: Spells no longer cost Mana to cast; the only limit is the amount of uses it has, so you can now spam a spell to your heart's content! There might be a few exceptions in the future, but none for the demo.
Enhanced Movement Mechanics: All actions are queued so that gameplay feels even more fluid.
Bug Fixes and Optimization:
Numerous bug fixes: I've kept addressing several issues reported by you. These fixes include resolving gameplay issues, graphical bugs, and other minor problems that may have affected your enjoyment of the game.
Please note that previous saved files and settings are not compatible with this new version. This is unfortunate but necessary; please forgive the inconvenience.
Thanks for all the support and feedback! I hope you enjoy the new features! Feel free to share your thoughts and suggestions with me on Discord to help make Commander Tiberius Troubleson better!
Have fun exploring the world of Anarth!