I am level 58 right now, and I'm trying to collect stars in all of the chapters. But the sudden death is very hard and I only get low XP.
For example, for the chapter Desert Freighter, the most I've ever gotten is 34 XP. No matter the strategy I use, I only get 31-34 XP. But I never get a star, even at 34 XP.
What is the best way to gain XP? Should I avoid upgrading my towers, use only one tower or create a tower near my base?
Desert Freighter is completable by building just one BBQ electric tower near the start (there is a Secret Spice achievement for this too!).
To star a sudden death level, you need to run all waves early.
To get the most xp, create a tower near your base!
It's really only possible to maximize either stars (nothing touches your bases in normal/air attack, or run all waves early like @tonycoupland said) or XP (let them get closer to your base, like @fredley said). I think it's easier to go for XP first and build up your upgrade points, this'll make it easier to go back and have an easier time getting stars. If you're looking to get a high score for each map, then build close to your base and maximize your career builder upgrade points. But if you want to just accumulate XP, just play Madagascar over and over again, it gives you roughly 5x more XP than other maps.
