Hey thank you so much for playing!
The restart instead of undo button was a conscious game design choice, as I wanted to encourage the player to try a different approach to reaching the exit, if their path failed.
This choice actually would've made more sense if I had kept in the levels with moving exit...I couldn't due to some technical issues though.
Anyhoo, I will surely reconsider an undo button as an accessibility option in future 👍🏼