It used to be unconstrained vertical movement as well but then you could sequence break the game by flying over all the gates, crates, and goblins and head straight to the final boss, haha. If I ever do a full release, vertical movement will be unconstrained as well and the environment will make sure the player can't escape. Then I can do things like spike pits and sawblades to dodge to help break up the story/combat.
But thank you so much for playing and I'm glad you liked it!