FleroGames' upcoming Abyssrium Pole has recently hit one million pre-registers, which is very impressive, particularly for a fairly casual looking game. Those who have pre-registered will receive 1000 Pearl when the game launches on 8th January which allows them to buy various in-game goods.
It becomes a lot less surprising when you realise that it's a sequel to Abyssrium, which was an exceptionally popular title, having amassed over 10 million downloads on Google Play alone. Despite this apparent popularity, you'd be forgiven for having never heard of it before, particularly if you're not massively into more casual games.
Essentially, it's a casual aquarium building game but on a grander scale. Instead of starting with a fish tank or an entire sea park, you've got the Arctic Ocean instead. So that means rather than being limited to smaller fish you can have big old whales roaming about too. You can populate the ground above ocean level too with penguins and sea lions.
It's intended to be a fairly relaxing experience, with simple tap-based controls and chilled background sounds such as droplets of water and whale song accompanying what's happening on screen. It has a very pretty low-poly art style too that is very inviting, even if there might not be enough gameplay to keep me interested for very long.