just had this idea randomly cause the game is so difficult (skill issue i know) so what if when doing solo runs you had the option to manually "save your game" and what it does is saves your current defense (including buildings, units, their positions, stats and all. im sorry for the coding pain this will bring). It saves it in the current wave you are on for example tide 9 (i hate tide 9 tempered javelins 😡) so if you fail miserably you can load up your save, start from the beginning of (the countdown of) that wave and test out a different strategy without having to spend 10 minutes replicating your early game strategy.
this could also work instead as an automatic feature that saves every 10 tides kind of like giving you a checkpoint but the point is it'll exist for solo only
also i must note as much as this feature sounds nice it is so unrealistic for the game in it's early access state that it is in right now but when 1.0 release comes out i can see a QOL like this being added and it will be VERY COOL
so this is more just a suggestion for an update far in the future that i think will appeal a lot to the casual playerbase of this game :)