This is a nice little base sim/tower defence. Building towers (mostly extenders) all over Mars' surface is surprisingly enjoyable, and it will definitely turn into a metropolis in no time. Urbanisation of Mars eh? It reminds me of Creeper World for some reason, which is a very nice game I recommend trying. The blocky art style is very nice, with that metallic and industrial grey + blue glow for the player elements standing out against that orange Mars sand. It looks quite nice. The gameplay loop is simple to understand, and it makes sense within the game and with the theme. Nicely done!
For some criticism, I'd say the main issue is that it lags quite a bit. I tried to play the downloaded version as well, and it still lags after I place quite a few towers. This hurts playability quite a lot on an otherwise enjoyable game. The map is also huge and makes finding the spots for the antennas a bit hard, and it doesn't help with the fact that there are no landmarks after leaving spawn. For some UXs I would really like to see some controls hint on screen at all times, given that I press the incorrect number for the 100th time by now. There are other minor issues, such as a very slow early game, the possibility of a softlock, no ability to remove buildings, need to guess where the exact position is even with the highest ping, enemies at night being a bit weak etc.
But anyway, I think this is quite a nice game. Good job!