One thing that bothers me.
Each level is so short that once I’ve finally built enough defenses, a new level resets everything. Feels redundant having to rebuild everything.
Compare it to Desktop Tower Defense, where you can build a maze and upgrade towers that last you the entire game. Could you imagine that game if you had to rebuild your entire maze after each wave?
In an old C&C game (Red Alert 1 maybe) I remember playing a survival mission. I had to defend a base for some 20 minutes with limited units and resources. I had wave after wave coming to attack me. It was quite fun.
Maybe something like that is missing. You are defending a base in your game, why not have a army style base there instead of just one building. You really don’t need much, just some rectangle with entrances, made up of those barricades, with factory, main building, and some limited initial towers.
Even level should maybe contain 3-5 waves of baddies, trying to crack down your base, hitting it from every angle, breaching walls, killing towers. Would make the player much more anxious trying to keep his base alive, repairing structure, rebuilding barricades.
Oh yea, being able to build towers “everywhere”, I’m not sure about that.
But, you’re completely free to ignore me