I have just finished adding in the new weapons system! So now what happens is theres a GREEN and RED section to the RIGHT hand power bar. This is your weapons power.
IF you get enough coins (fill your coin bar) while the weapons bar is in the green - you power up!!
IF you fill your coin bar when the power bar is in the RED you only recharge.
IF you DONT get enough coins to do either, you drop a power level.
IF you are on level 1 and the bar drops to 0 - it STAYS zero until the coins bar is full and then recharges.
This should mean that you HAVE to kill baddies and dive in to collect coins making you dice with death! Otherwise, you could just sit back and shoot which would be too easy.
It'll be interesting to get feedback once the demo is released....