In this mode you can’t move around but you can rotate your ship by moving mouse left and right or pressing “←” “→” on keyboard. Your ship will be centered and there will be some asteroids slowly floating near you (like this old “Asteroids” game)
Small ones can be easily destroyed while big ones will crack apart into smaller ones (Like “ᴀsᴛᴇʀᴏɪᴅs! no, realy” wave from CI2). In this mode gravity works like in CI4: If asteroid drops you a gift, it will fall in opposite direction from your ship’s look but items like keys or food will fall down regardless your direction.
The main problem it isn’t too unique to be new game mode.