Ben 10 Ultimate Alien: Cosmic Destruction/Eiffel Tower

Level 2 : Eiffel Tower
 * Optional aliens: Swampfire, Water hazard, NRG, Amfibian

Once you are in this level, behind you is a sumo slammer card so run and take it. After that walk ahead and you will see a poles at your right. The only aliens that can hold on to the poles is Swampfire, Bigchill, Spidermonkey, Water hazard. Once you have get pass two poles youl'll have to do the same thing again but this time on windows.

After passing the windows walk on the stairs and you will see some enemies to take care of after that use Water hazard water blast to open the gate

After passing through the gate, their is a pipe with green gas coming out. Use Swampfire's fireballs to ingite the gas to make the wall explode then change to NRG to get through then more enemies will come. After taking care of them the gate will open and you can continue.

Then when you have entered the next area will be two enemies on a high building and they will be shooting, so what you need to do is to change to NRG to melt the glowing pole