I love this game, really fun. But there are a few things that make it hard to get past the second wave once you defeat the first boss.
1. It's too RNG dependent, both for world gen and upgrade selection. A few things to fix them could be to have it so when generating the world you are guaranteed to have one side blocked off by trees to force enemies to go around, as well as guaranteeing one big choke point to force enemies to go in a single-file line, or you could allow the player to place down like 8 trees wherever they want after the world has been generated. If you don't have good world gen you'll be overwhelmed very fast in the second enemy wave. For upgrade selection, having three choices and being able to re-roll once every upgrade would be nice, it'd give more chance to get the upgrades you want.
2. A Luck stat would be nice to be able to upgrade, whether it be for an orb or for the turtle/house. Upgrading it would get you a higher chance at getting gifts, as well as being able to spawn coins that are worth more so you can upgrade faster.
3. Being able to choose what orb we get after defeating the bosses would be nice, that way we can get good combos that allows us to defeat enemies easier, having it be random sorta forces you to divert from a plan you had so that you can have both orbs work well.
4. The ability to see our stats. It'd be nice to be able to see our stats, and see how much they'd increase if we get an upgrade. It'd also be nice to be able to know how much a item or upgrade increases whatever it is that it upgrades.