But addictive, but jelly defense is a lot of fun if your device can handle it. Minimum specs are a dual core, my nook tablet plays it great, and my LG spectrum handles it, but my Samsung moment and HTC Evo 4g cannot play it.
I spend a good bit of time on armored defense and a td variant cartoon wars. Arel wars is fun as well.
Other td games I've enjoyed, that are still installed in my nook:
Guns n glory
Living dead defense
Tower raiders 2
LG Spectrum -- Rooted and running CM10.1 official M2 thanks to TDM (and too many others to list).
B&N Nook Tablet 16GB -- running CM10.1 with 10 finger multitouch