I have to say, I played this game solely to earn a hard badge. But this ended up being one of the best puzzle games I've played on Kongregate! The way you are introduced to new mechanics every 20 levels was great and in the last couple levels you really had to think. The last level had me nervous as it looked ridiculously hard but it ended up being an outro to the game! One of the easiest 5 stars I've ever given out, it was fun from start to finish.
I can sum up my comment in the form of a poem:
There once was a game called Red,
If I didn't shoot the meteors I'd be dead.
Don't mean to sound like a whiner,
but this game could use a timer,
and an asteroid just hit me in the head.
For a browser shooter this is pretty well made. Can't say I "like" the micro-transactions but with it being free to play I can't be too surprised either. Maybe add some cosmetic items/customization for players who spend real money and less guns, to make it fair for free players and paying players alike. Look at Team Fortress 2 for example, one of the most popular free to play FPS games out there. The majority of their revenue is from cosmetics like hats, so the combat is still balanced between "premium" players and free players.
The game is a blast for awhile, but at a certain point it just feels like work. The hard badge isn't impossible or anything, but after 30 waves or so I just don't feel like playing anymore. Overall a really enjoyable game though, 4/5!
For all three badges in one game: Play on the first level (hard), put tack shooters in all the round corners (fully upgraded) and throw a cannon in there semi-close to the beginning (upgrade it as needed.) That should hold them back for you to save up for a super monkey. Place a freeze balloon in the top left round corner (fully upgraded) and finally when you can afford it, place down a couple beacons to boost the range of the towers. Doing this I didn't even need to use road spikes to save myself once, and apologies if this is already known. Great game!
The sounds it makes when you pass through a tiny gap going 100's of MPH is a beautiful thing lol. Great game, only negative thing I can say is that full screen isn't working for me.