Thanks for the great feedback!
- RESPAWN - this is something I fixed after creating the demo version, but I'm just finishing work on a new map, so once that's done I'll create a new release that contains both.
- EDGE OF THE MAP - this is a technical limitation of my code, but I can understand the frustration with it so I'll take another look at resolving it.
- LIVES - I think myself and the testers probably got too good at the game over time, so I was more concerned about it being too easy than too hard. Building an extra-life feature isn't difficult though, so I'll take a look. It would be a shame if people didn't get to visit the later levels because of this.