Last year I made a set of levels for my little kids aged 2 and 5.
Especially my 5-year-old loves to play Boulder Dash and he really loves to create his own levels with the editor in Boulder Remake, but he's not yet fast and accurate enough to be able to do more difficult levels where evading rocks or beasts is necessary.
The levels I made progress from extremely easy to quite difficult.
Each cave has 5 levels.
Cave A1 can be played by kids of any age whereas cave P5 is pretty hard even for experienced players.
Demos are included for every cave.
Here it is:
http://users.telenet.be/adelaar/ToddlerDash.zip
Have fun
P.S.: one of these I'll make a compilation of the best levels my 5-year-old made