Okay, wow.
The flash game I'll mention isn't that old, so it won't sound that cool when I say, "The last time I played a flash game this long was on Bloons TD 4."
I've probly stacked up 10 hours on that game, including time at school and at home. I started up this game because I was looking for flashes to rate (so I can get my exp), and I had no idea what was in store for me! I did not plan on spending my night on a flash game, but that's what happened.
I flew threw Endurance VI and I've been playing for about 3 and a half hours straight now. That's how g'damn addicting this is. I'm a lieutenant only because getting expert scores are pretty tough. You have to have a lot of upgrades on your towers to get expert scores. I found myself getting 1000 or less expert score on the latest mission I'd unlocked, so you think it'd be easy when I come back later with more upgrades, but it's still hard.
All upgrades except the top 4 are useless, however. If you want to do damage, upgrade nothing else. I never even wanted to, and I'm glad I ended up not doing it, because the poison, freeze, multi, and basic towers are all useless by mission 27 (which is the mission I got bored at). The only reason I still use fast towers anymore is if the overpowered super towers leak, which doesn't happen often. I want to get to the last mission, because when my defense gets very powerful I cannot really use it cuz by then, the level is over, and I have to restart. So I'm sure the last mission lasts a jillion levels and I can actually have some fun with each tower.
The music was ok, but after about half an hour I shut it and the FX off so I could play my own music. Good flash games don't do that to me, but then again I've been playing for the last 3.5 hours.
So anyways, I hate when games end up having a component of it be useless. I really only want my super and fast towers, and I only need the top 4 upgrades to win. Aaaand the music is useless LOL