I made it all the way to Wave 140 before the game started slowing down my computer to the point of being unplayable. It was fun for a while, but got a bit dull after strategies. On the topic of strategies, being able to be make in seconds until the end would be pretty neat as I always wanted the x10 Damage right before the end and would have to eyeball it.
Quite a bit of the game is fairly unintuitive. While the most fun I had was with figuring out how "Metal x2"worked and messing around with it, you should mention somewhere that it also boosts Weapon progress. Metal snowballing was also likely the reason it slowed my browser down to such an extreme degree. Recon Mode on the other hand, was never something I figured out. Given that overkill doesn't work in Recon made it more about time, but even balancing between that and metal, I wasn't able to get much in the way of progress, to the point that I was able to move the blue bar quite a bit during my first ever run, but every run afterwords would barely move the bar. I never made it out of 1/2 hp. Troops and "Recruit x2" also took me a tiny bit of study to figure out how they worked, but I think that one is more on me than the game.
It also barely feels like it fits the theme. Yes there is a timer, but I don't think that is enough on it's own (mind you this is my first game of the jam, so I don't know how difficult it is to include the theme at this time; I may change my mind after more points of comparison)
Overall, it was fairly good game for the majority of its runtime with just some minor issues in explaining itself