Thanks for leaving feedback! When you open the game, try choosing the lowest resolution available in the dropdown settings. I made quite a few performance-related mistakes (i.e. too many lights, expensive shaders, and large triangle count) that will all be done correctly in the next project. If you want to add me on Twitter or Discord I could send a custom build with performance fixes to test out. As far as checkpoints and saving, that will be implemented in the next one as well. This was meant to be played through in one sitting (10 minutes). I'll add a menu though, some people have had issues with hitting escape and it closing when they were close to the end.