Nice little fun mini-game. A little rough around the edges at times but overall it's fun! One critique that I have is how often the extra lives pop up at the bottom. They happen just often enough that you can last indefinitely. I would either slow down the conveyor belt or shorten the timer. That way there's still a chance of a game over. Extra lives should feel extra, not necessary. Although, at the same time I can see it being quite frustrating to get a game over on something like the final level and having to trek through everything. On the other other hand I was expecting this to be a memorization type of game, but instead it turned into a "get into the dev's mind" kind of game. I actually think it would be hilarious if you played on the idea of messing with the psychology of the player with your bomb placement. One level it could have the bombs form an arrow that points to a single bomb, and players will be like "is that really the right choice? Or is the dev trolling?" You did a bit of this near the end (I won't say where) which I appreciated, but I wish you had leaned into it more.

With that being said, for this just being a game "for the purpose of learning Godot", it's good! I can see that you're learning a lot of important things!