Love the joystick for mobile users.
This idea could even be taken further - it would be really cool to have terrain that is more difficult to traverse. I'm also intrigued by the lack of walls. I think something like a hedge maze would be really fun!
* Cannonball!: Tb ba gur qvivat obneq va gur cbby. Fbhgurnfg sebz gur fgnegvat cbfvgvba.
* Treasure Hunter: Teno n zrgny qrgrpgbe gura frnepu arne gur yrsg fvqr bs gur ibyyrlonyy svryq. Abegujrfg sebz gur fgnegvat cbfvgvba.
* Goal!: Fpber n tbny jvgu gur fbppre onyy. Fbhgurnfg sebz gur fgnegvat cbvag.
* S'more Please: Teno n znefuznyybj sebz gur ohpxrg naq chg gurz va gur ovt sver. Gnxrf nobhg gra frpbaqf. Abegurnfg sebz gur fgnegvat cbvag.
* Cat Person: Crg gur png va gur ubhfr. Abegujrfg arne gur fgnegvat cbvag.
* Take a Seat: Fvg ba gjb punvef.
* Slide!: Tb ba gur ovt fyvqr. Rnfg sebz gur fgnegvat cbvag.
* Beachcomber: Svaq nyy gur frnfuryyf.
* Green Thumb: Jngre gur irtrgnoyrf. Fbhgujrfg arne gur fgnegvat cbvag.
Edit: I looked at the source though and I don't see anything else clickable in the cave... No hidden secret badge either, maybe it is just for ambiance.