Glad you like the mechanic and see it having potential.
For your comment on sound, we don't have any. We didn't have a sound designer nor the time to implement sounds. The team who worked on this game wanted to focus on improving their own skills whilst fitting the game jam around their own personal schedules.
A tutorial would have been great, and if this was a fully fledged game with further development, that would be something we would focus on in the latter stages of design. We did a lot of internal testing and prototyping of further mechanics and ways to improve the gameplay which made us lack time to include this in its current stage. Though, we would like to include a control layout on the itch.io page going forwards (:
Undoing placements isn't something that is currently possible as we wanted to focus on getting a basis for building complete before focusing on further mechanics.
Thanks for your feedback!