Bloons TD5 has heaps of new features including all of your favourite towers from BTD4 with 8 awesome upgrades each instead of 4, and two brand new never before seen tower types. So much new awesomeness: tower upgrades with cool Super Activated Abilities, new Bloon types, fun new tracks with moving parts and tunnels, powerful Special Agent towers, Daily Rewards, Special Missions, and Daily Challenges - a fun new challenge to play each and every day! Updates are coming all the time, and your progress is tracked for ranks, upgrades, and achievements when you log in using our new NK login system. Have fun!

4 was better

Why was 4 better?

I have this on my phone its so fun

I think 5 is great since you can play with friends.
Top level I achieved was 109 (I think) on one of the medium maps but got way too laggy and had to quit out of it :<

5 is basically PTW. And I left my device on the charger like 24/7, got to like round 300 on apocalypse mode before I decided to stop the game lol. Tack shooter + ice tower + a few support towers = unpassable if you pop the blimps earlier in the track.

Bloons TD was like, THE game before transformice.