The sushi recipe says "Get to level 15", not "Complete level 15". Those are two very different things. Some clarification would probably not hurt anyone.
For anyone having problems unlocking the achievement, this is what I did to solve it:
Once you finish the game, go back and select the last level again. Press skip, see the ending once again, and get your achievement.
Great game! I would suggest automatic coin pickup (perhaps via janitors), and let the extras window stay open even if you buy something. Perhaps even a log of good/bad combinations as you find them?
Compared to a lot of the other, more innovative tower defense games on Kongregate (Gemcraft, Don't Touch My Gems), this is too slow, too simple, and doesn't seem to have a real goal. The towers also need more levels or more upgrades, because they become really underpowered just a few waves in. Add more tower combinations, a speed-up button, and more levels/upgrades to the towers, and it might be getting somewhere.
There should be a way to either reset tech points or at least choose what type of cannon to use. I have to re-do the whole game now, because the first rank of the plasma cannon is utterly horrible, and I have no chance of passing the current level.
The only problem I can spot right away, is the lack of certain hotkeys: Upgrade tower, sell tower, deselect tower and so on. Oher than that, I love it. The level-up system is quite nice.
This game is superb, 5/5! But the grand master puzzles should've had some tweaking. mostly because the numbers are so damn hard to read, and they expand into the playing field and so forth. a bit bigger size on this and you have yourself a winner.
Should add the possibility to either sell or remove the planets, and also if you press the Upgrade Planet button, you can't cancel it. You have to upgrade a planet to be able to move on.
Other than that I enjoyed this game a lot.
This game rocks! Didn't like it at first, but kinda getting to know the game now and it's awesome! I do have one complaint tho.
I don't care what's said, the revenge waves is a shitty way of compensating for the fact that you're fighting a computer opponent. He can regen enemies as much as you can, and the spell cards do in no way justify having 400 mobs thrown in your face just as you're about to win the game. It's a lame aspect, that's all. Other than that, 4.5/5 from me.
Loving the game, but you should be able to skip the intro video at least. Having to reload the game and being forced to watch the video each time is kinda troublesome.
Getting the 500 headshots badge is quite easy. Just do like me, die alot :p Even if you didn't finish the level due to dying, the headshots will stack up, and 500 should come easily.