I entered Level 2 and found that map is generated with glitch. I clicked the Reset level progress. The game generated another broken map. Now, whatever I do, it keeps the second broken map and I can't go on.

Here's how I solved it for the first time.
Disable server sync for saves
Go to C:\Users\-USERNAME-\AppData\LocalLow\Unfrozen\Iratus\-WEIRD FOLDER- (backup first, of course)
Delete all save_level...map.mapsave and .mapsave.bp
Start the game. It generates new map.

PS: I did it again on level 3. Except, I can't fix it this way again. Game do not save me on level 3 now, so I can't just delete the map. Instead, it keeps me on level 2 and when I move on, it generates the same broken level 3.

PPS: Ok, I fixed it again. The thing was to make game save the position. So, on the new broken map you have to upgrade the minion, tower or something. And then do what I was doing in the first time.
But you devs better do something, because I feel like this will happen again on the next floor.