He loved trying to scoop up the ice cubes and "catch" them with his containers as they were melting. Since they cubes are coloured with food colouring be prepared to end up with coloured fingers as well if your little wants to touch them and play with them as they melt in the water.
We took turns adding different coloured cubes to see how they changed the water colour, and put the unused cubes back in the freezer for another day of play!
Watching the colour disperse across the water as the ice cubes melted was really cool and the next time we try this out I think we'll add a whole bunch of one colour and try not to touch them for a few seconds so we can really see the colour spread.
The boy-o had a great time playing at his little water station to try and beat the heat, and the addition of the coloured cubes added a little bit of extra fun. It's definitely a fun and simple activity that we'll be trying again another day.