So I've played this a lot more, even getting my level 1 clear thanks to the coins to crit chance relic, and I think I've found a couple of bugs.
First, the Armlet of the Forgotten Soldier can be broken by spamming an arrow key in one direction. This results in the player dropping a coin every time they let go of the key. As such, I'm able to rack up 500 or more each new area by chilling in my base and spam walking, then occasionally running loops around when there's a lot of drops waiting for me.
Because of this, I've gotten my hands on a LOT of towers. More than I ever expect I'll have again. However, a consequence of this when the merchant sells me towers, they claim to be max level but don't have max level damage nor show max level (they'll only list level 1 or 2).
