I have played this game for a while now. It is very enjoyable. Every now and then everything started to flicker and turn black though which prevented me from continuing the run.
Since the game doesn't seem to have an end and since towers can not be removed, the game is very end game focused.
The towers I got, weren't the towers I needed. I didn't want to waste precious space. I think a "remove a tower" card would be a great addition as it would allow for more experimentation in the early game.
My plan for the late game was this. It splits the maximum available dps evenly across all lanes. I sadly wasn't able to see it in action because of the flickering issue.
All in all this game has some very interesting mechanics. I feel like combining it with deck building aspects could be even more interesting since the players will be responsible for the cards they get. I am interested to see if you develop this idea further.