5 minutes is really accurate! I just finished it in 304 on speedrun mode :) quality lil' game, the level designs were quite good! makes players second guess enough and undergo trial and error (y)
Woo! Double Cash power up! Hope one kid comes so I can actually benefit from it! Seriously, this game's so dull I think it gave me foetal alcohol syndrome. If you're just here for badges, upgrade the dual pistols to full, then endure holding the mouse button until you've got enough money to fully upgrade the auto-cannons. That's the quickest way to end the nightmare.
All that playing - Just to realise that the Pirate Ship in the final level creates way too many smoke bombs and therefore about seven million times too much lag to even possibly finish it. Don't bother striving for the hard badge, it's a great way to waste your goddamn time.
How to win:
1. USE PAUSE. You can do all commands while the game is paused, minimising the damage you take while maximising your damage output and overall efficiency.
2. I got both badges and the card in about an hour without using spells. (except fireball is useful on level 2's special challenge, mostly for its range) Fully upgrade Wealth, then fully upgrade Cost. (the two far right upgrades.) This gives you the most plants in the shortest amount of time, giving you a big leg-up over your opponent. Then fully upgrade attack, regeneration, then critical (you can go regen, then attack if your plants are getting killed too quickly, but your income should make it easy to seed new ones).
3. Just use logic. If one of your units is close enough to attack and one is too far away, use symbiosis to support the closer one. (although sometimes its beneficial to leave the further one in growth mode)
Hope this helps!
For those of you striving for the hard badge; level 30 is probably the hardest. (its the one i died on the most) try to wait a millisecond then run off the main platform so you fall diagonally (falling just to the right, missing the buzzsaw) and then try to jump up and diagonally toward the goal. Eventually you'll get it!