This game was made for a game jam event where the limitation was to use only 4 buttons, so we adapted the character's actions only on those buttons.
Regarding the distance from the checkpoints, I think that because the game is small, there is not much priority in facilitating the character's save over short distances, thus making the small game a little more difficult to finish.
And in relation to placing the checkpoint next to the lever, let's say it was a joke we did. we know that returning by the same route and something frustrating then...
We just made a new update in the game, where we added new buttons for each action of the character. And we added the teleport between the portals already activated, when you are near a portal just press the button (Ctrl) to interact with the menu of available portals.
I hope you like the new updates.
Thanks for the feedback ...