easy way to upgrade: go to the shop with a lot of money, buy whatever you want, exit the shop, enter a level, click the pause button and go back to the main menu, start and go to the shop and your money will be back along with the upgrades you bought earlier
this is one of those games that is challenging but you dont live long. like other games like any of the bloons tower defence games, you live a long time and if you die you restart the whole thing. but in this you live maybe 30 seconds at best per level. maybe not even 5 seconds. so you can restart without taking forever. it doesn't get boring or get annoying when you die.
i would suggest playing meatboy first to get used to the keys. they slip and are very hard to control. there basicly the same game though. this is is more challenging in my opinion
btw that game on the neo geo whatever is called raiden. theres a game on crazymonkeygames.com called raiden X. its like the modern version of the old one. should try it if you like it
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