What the hell are you thinking with these upgrade costs? I'm not grinding already finished challenges 50 times just to have a tail fast enough to dodge through one more.
What you have here is the rough outline of where a decent game might start. Come back when you're more than 20% of the way there and then maybe there'll be more to say about it.
After the "demo" battle, that stupid lotto thing popped up, and the only obvious button was to spin. Long story short, I get back to the game and discover I just wasted a precious resource. 2 hours later and every option explored, I haven't regained a single gem, but have tons of these "crystals" that apparently have no use whatsoever. I'm half-way to level 3, but what few items I've managed to scavenge just get damaged and lost, there's no room to store replacements in advance, and I can't even reset my account to start over and at least have starting gems.
So yeah, great job. :( Terrible UI on usability and lag--why on earth do pop-up screens take longer to /close/ than open, and where's the match quit button?--terrible balance, and pay-2-play (my time isn't free, and the gaming satisfaction if you don't pay is abysmal). Congratulations on a well-earned 1/5, usually reserved for no-budget jokes.
I don't know how anyone could make level 250 in apocolypse mode. It's not the challenge, just the patience. Around level 40 I went to bed with the track laid end-to-end with maxxed out spike generators and as much firepower as I could load on the map. Got up the next morning and the ZOMG balloons weren't even penetrating 1/10th of the way through my defense, but I hadn't even reached level 90 yet. That's 8 hours for 50 levels.
We REALLY need to keep tracking mouse movement off the edge of the game. And if we can't, add a border. Otherwise it's impossible to maneuver near the edge and you stall when you weren't actually cornered.
Maximize rear ride height and minimize front ride height for optimum performance on most maps (excluding bonuses where you have to back up). High front ride height just slows you down and /reduces/ road contact, whereas low rear height also slows you down and gives you less ground contact.
Can we get some better text contrast please? Using a gothic font is hard enough to read without dark-on-dark leaving me trying to visually parse the light drop shadows.
You have to click through quite a few pages to get an actual price, so I'll save you some time: with the discount it is about $5 US. Also, not until you've bought it do you ever find out you're expected to install Adobe AIR. Developer, you need to be more up front about these things! I'm /almost/ annoyed enough to demand a refund/return it.
Let's put the developer's link right next to the pause button...and provide no pause hotkey. That way when times get tough, you can flip to another tab INSTEAD of getting a moment's breath to deploy rush units.