Here's my let's play before my wall of text review:
I really liked this game. I said it in the video, but it is really solid for an alpha build. I have some nitpicks though. Will the objects be destroyable in the future by the main character? In my second attempt, I accidentally trapped myself and rescue came but I couldn't leave since I was trapped. I also didn't like that a white square was the icon of the thing I was going to put down, because people could get confused if they hit another thing by accident and placed something they didn't want to place. I don't know if it will be changed later on, but I suggested like a semi transparent version of the item I am going to place so there is a visual cue of what I am placing. I was kind of lost in my first run, but that's because I overlooked some things from the itchio page. Like I didn't know that the yellow number was the available power until later on. However that's just me overlooking things. When everything blew up at the end of my first run, it gave me a little jumpscare since I wasn't really expecting that to happen lol. There also seems to be a bug where rescue arrives, and I am stuck so I can't get to the rescue, and the timer kept going after it hit 0 and went to negative times. I have no idea what's on the list for future updates, but I just wanted to point things out.
Onto the positives: I really like the idea of building your own base and defending against waves of things, waiting for rescue. I also like the music. I didn't get bored of it, and it fits the game in my opinion. The controls are solid and responsive, and overall I liked it. A really good demo (despite my nitpicks) and I enjoyed it a lot! It has a lot of potential and can't wait for future versions!