Decent concept, somewhat buggy execution.
The basic idea - carrying metaprogress over in a tower defense game - is pretty sound, and while it has been done before, I do like the way this game approaches the concept. What's more interesting is that you're doing something more like area denial - preventing enemies from leaving the map in particular directions - instead of protecting a brick in the center of the map.
You have three tower types, which, although not differentiated enough, do seem to serve some very slightly different strategic purposes. (Recommendation to the developer: Laser turrets should probably be significantly longer range than anything else, but also lower damage. Also they should probably do constant damage as a beam, but be more prone to overheating. Plasma turrets should probably be much slower, but do something like % of enemy max health damage.) Each tower has, at present, two upgrades, of which the first is basically mandatory - the starting power of each tower is quite underwhelming. (You could probably boost the starting power by 50% and they'd still be a little underwhelming.)
You also have traps, or at least multiple instances of a particular trap; it looks like this is intended to be more in-depth than it is at present, which is that there are currently static points on each map where explosive barrels line one side of the road. (It looks like one map has some kind of barricade that does damage as well, but this appears to only impact civilian vehicles at present.) These do quite a bit of damage, but consume resources to reset, and additionally take time. Said resources might be limited? Although sometimes they seem to respawn over time. More traps would be nice, here, as right now the resources don't seem to be a limiting factory of any kind, and traps are definitely a nice early game boost. (I think there's an ideal strategy here involving building only power plants in the initial phase, and use traps to thin the enemies out, but I haven't played to that yet.)
Currently the basic difficulty of each of the five maps is pretty low, apart from a couple of items I'll get to in a moment. There is a hardcore mode I have yet to investigate that promises greater difficulty.
Before you go into each map, you pick three modifiers (the game calls them skills) which give your defenses small bonuses; one, for example, causes enemy vehicles to slow down once they reach a certain (percentage?) of health.
Additionally you have a technology tree with three branches, each of which focus on a particular kind of tower. You (very very slowly) gain experience playing the game, which, as you reach certain (high, relative to the rate of experience progress) thresholds, you gain new enhancements. These are mostly (quite substantive - no "5% increase" nonsense here, offsetting the glacial experience gain pace) bonuses to the attributes of that tower type, along with some increases to the effectiveness of the traps.
For each map, you are playing area denial; your goal is not to prevent the enemies from destroying your base, but to prevent them from passing through the area (the use of "armor" to represent your ability to fail at this seems a bit odd, but, eh.). I actually quite like this as a concept - except it isn't clear when first starting in some maps where you're trying to prevent the enemies from going, which feels slightly "off" from a gameplay perspective. As you play, in theory, you're balancing constructing new power plants with building new towers, as power plants, in theory, give you the resources you need to construct new things. All the while the infrastructure is randomly (maybe? It seems loosely correlated with enemies being near it) breaking down, and you're having to move around the map to fix power lines and rewire wind turbines.
I emphasize "in theory" because it doesn't quite seem to work that way; I can't really tell a difference between one power plant, not upgraded at all, and four power plants upgraded to the second level, in terms of the construction resources produced. (Called battery power, in the game.) Some kind of visual indicator over the power plants when they add battery power might be helpful, if indeed they're doing that; additional battery power instead seems tied to damaging enemies?
Additionally, I -think- downed power lines drain your power "capacity" over time, which would be neat, except fixing the power line doesn't seem to immediately (or possibly ever) restore the lost capacity. The final level was, for me, primarily an endurance race of building new power plants to restore capacity that seemed to have vanished forever. (Was there a power pole I couldn't fine that was just constantly draining my capacity? Maybe. They're really hard to find / see in that level.) My experience of this, whatever the intent, is that there is a power capacity bug causing capacity leakage. It's hard to tell for certain, however, as some things reduce your power capacity (like the period of time it takes to reset a trap), and other things increase your power consumption (like towers); however, at one point I got a notification that one of my power plants was at full capacity. (What? Why? What caused it to decrease? Or was that just a power plant finishing coming online?)
UI responsiveness is a big issue, particularly as concerns "double clicking". I turn the speed down whenever I need to set off the traps because it typically takes several attempts to get them to go. Additionally, there are some menu options that ask you to double-click, and these can take several attempts before they accept the command. In the map, you click to collect certain resources (which, oddly, the game permits you to do even while paused), and it can take a few clicks to get it to acknowledge the request.
Then there is the technology tree. There's a reset option - I decided, after hitting the first experience threshold and getting an additional point, to try a different tower, and reset the technology tree, which took a few attempts at a double click to get to work. And went from three technology points to one. After another reset, I got two. After another reset - one again. I think the code that's supposed to add the different rank technology points together is instead just returning after it finds the first rank in the list? Or possibly there's an off by one index error and it uses all but one - hard to say without hitting the next threshold.
The game could also use a bit of optimization, or else just needs to let inactive threads sleep for a bit (I suspect the latter). It doesn't seem to be mining cryptocurrency, but for as minimal as it is, it sure gets my fan working overtime.
Overall, in the current state (released yesterday, and still in Early Access, so my expectation is that it doesn't remain in this state), I find the game a bit of a mixed bag, but on net I find it entertaining.
