Are you asking for a way to re-roll to different rewards?
There's no way to give me money, but I appreciate the thought :)
Thanks for playing! And thank you for the suggestions. Adding the ability to right click + drag to remove multiple tiles is a good idea and I can probably add that.
With respect to your mod suggestions, I'll have to do some investigation. I'm not sure how well my infrastructure would support those behaviors and I'd also need to make sure it is still intuitive to new players.
While it is not an elegant solution, if you want to experiment with your grid without messing it up, you can leverage how the autosave works. The game is only saved immediately after you pick a reward and when you press the Start button. This means you can mess around with your grid, quit to the main menu, then hit continue to restore the grid state.
Thanks for the feedback. Increasing the maximum health after each boss may be a good idea. As you said, the enemy DPS goes up as the game goes on and the player will bleed health faster in later waves.
Being able to flip tiles or move the source nodes would give the player more freedom, but we have to be careful about making the puzzle aspect too easy. There needs to be some friction between what the player wants to do and what they are able to fit in the limited space.
Thanks again for giving detailed feedback!