WOW! You are the first one made it so far i guess :-) Congratulations.
Yes, unfortunately there is no ending. The whole game started with the idea to be super minimalistic with controls like atari, meaning you have a joytick and just one button. this is why in the first version i implemented it like you need to press fire and then a direction so he mines a block. same for up. press fire and move up makes a ladder. but then people complaint or gave good suggestions so i added mining above, i added torch and so on.
But because of the minimalistic approach, i did not want to throw tons of items and mechanics into the game, i was quickly out of idea and then new problems started. If you get deep enough, its a chore to always walk up again, sell everything and walk all the way down. So as you said, some kind of teleporter or maybe a checkpoint after 25-50m would be good.
Then i added chests, for some excitement but they are just ore,ladders and torches inside. Then the question is overall, whats the purpose of digging down further down. What is the goal? And i still have no idea. I don't want to just copy other game ideas.
If you have any suggestions, i would be glad to think about them and maybe i can implement new things :)

