As a GDevelop user myself, kudos to you for pulling this one off! Overall the visuals and the sounds are excellent. Also with small shakes and animations, everything feels "alive". The game itself could've used a bit more variety of defenses. It's pretty straightforward to fortify just one room and select it to be attacked. I wish there was more incentive to fortify other room or to build defenses. The music is also pretty engaging.