Does this run without any curses? Very impressive!
On my first run, I put single letters at the towers and only got as far as wave 1, a double C got me!
Then I realized I could put more than one letter, so... by wave 12, things started reaching my 3rd base. Does this game get progressively more difficult? I think it does, but I can't tell. It probably does because things reach 2nd and 3rd base eventually. You can probably make it more difficult by using more biased random generators that give more duplicate sequences. I think that's what you do anyway? You could also spawn more letters and/or make it go even faster.
Fun game, but once you set up your bases, there's really not much you can do, I doubt human reflexes can help much if you get in trouble...
Edit: By wave 21 I had lost 4 lives! But it won't go on anymore. It looks like it stopped. Did I win? :)