For this game I wrote the physics for the movement and jumping from scratch with delta-timing implemented (or so I thought) but then also ran into these same issues when testing the game and was unable to resolve it in time. I used the framework Love2D for this submission and spent a lot of time writing the core systems for the game when in hindsight it may have been more productive to use something like Stencyl or Gamemaker instead to get the base 2D-platformer aspects completed quickly and allow for time to focus on more interesting and important gameplay elements. Our team had lots of ideas for Kirby-like gameplay mechanics such as stealing magic powers from defeating enemies that I would have loved to implement in our game but were unfortunately not able to be included due to time constraints. Thanks for playing and reviewing our submission :)