Bloons is probably the most popular tower defense game on the market. They started as flash games - I have fond memories of playing the browser versions on computers in school - and have since moved on to full releases on PC and mobile.

The core gameplay is timeless and excellent. There are dozens of different types of towers, and throughout the years they've added in unique heroes with abilities, challenges, quests, and a ton of different maps. If you've got the mobile version, you can sync progress between versions and keep playing on the go. There are microtransactions, but they don't seem necessary in my experience.

Verdict: Endless/Timewaster

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