Having doors, trapdoors, hidden buttons, torches etc is the main idea of dungeon crawler genre. Yes, it's 'dungeon' crawler, not forest crawler, not spaceship crawler etc. It was that kind of game which evolved into open space fpp rpg. We are coming back to the roots.
So far you can see standard, old dungeon theme. There will be 3 more themes: abadoned mine, crypt and... it will be a surprise In almost all miedieval-magic games you have the same arsenal: swords, axes, bows etc. and spellbooks and wands ofc.
An important part of every rpg game is the mechanics. We don't want to adapt any D&D or other well known system. We will have our own, unique solution of stats and skills.
I'm not afraid of LoG, i'm even happy that it was successfully released and earned a lot of money - it means that players want to play such games and probably will accept next one, which will be similar in some matter and different in other.
The main problem is that most ppl now knows only LoG, and newer saw games like Dungeon Master, Stonekeep, Eye of the Beholder, Might and magic (1 to 5) and many, many others... They think that it was something original and our game is just a copy. They are not aware of the fact, that there IS an genre called 'dungeon crawler' and LoG just fits perfectly into it without having anything original.