This is a great game! I've played for more than 200 hours, and I'm currently building museums of all exhibits. But my panoptic pillar I exploded, and I found I couldn't rebuild it because I had unlocked panoptic pillar III, which is quite annoying for not being able to complete my collection. Would it be possible to build low-level science exhibits after unlocking higher-level exhibits? I think it would be nice for players to build science exhibits of the desired level in the next update and I wish you could consider my suggestion.

I never thought of that but actually... That's quite a good point ! I'm not too fund of the science exhibit (particulary the projects oneS, they have good effect, but i don"t know, not my style I guess), but it's weird the game doen't aloud you to built low lovel ones. I completly support your suggestion !