How to tile a "wet room" style bathroom?
If you have a specific tile in mind, and you have seen this in a store, simply try the slipperyness out by making it wet and rubbing on it.

There should be nothing wrong with using a pool tile for a bathroom (except maybe slipperyness), since a bathroom is made waterproof underneath the tiles. If the membrane is intact, you can use any tile meant for wet conditions. If the membrane isn't intact, you need to do the whole thing over and redo it anyway, regardless of your tile choice.

Now, I don't know what tiles you like and find pretty, but at least where I live (Denmark), you can get most tiles in sizes from 5x5 cm and up to 31,5x31,5 cm (and some up to 60x60 cm). Some smaller tiles come in sheets of mosaic tiles on a plastic net.

A qick search on my local stores yielded several mosaic tiles (30x30 cm sheets of 5x5 cm tiles) that were labelled as "not slippery" and generally tiles in all sizes and colours.