Hi everyone,
If you're struggling to make enough profit to beat the level there's a number of things to consider:
1. Are you generating enough income?
4 flat rides probably isn't enough to cover it. You need coasters in order to get more income up higher (and make decent profit). Now in Pirate Battle you already start with one coaster. Try building another.
2. Following on from that, have you optimised your rides and shops for maximum profit?
Make sure your rides always run at full capacity on each cycle. By default they only run at half capacity. Increase the prices. You can get away with a $1.50 - $2.00 increase on most rides and on some even more, especially if you've added scenery to the queue. I think I had an Insanity ride in my Pirate Battle park and charged $12.50 for it (and I think the default price is around $8). The coaster that comes pre-built in Pirate Battle you can charge $20 for no problem (if I remember correctly).
Increase all your shop prices - Cosmic Cow can be increased to (edited from increased by) $6.00 per shake no problem. Chief Beef $2 increase on each item. Make sure you are not missing too many sales at your shops. If the shops have big queues chances are some people are walking away without spending. Consider training the vendor so they can serve customers faster. Or add more shops to cater for demand. That said, don't leave shops open that aren't making you any money. Check the park management screen (rides and attractions tab to see how much profit you're making) (see next tip).
3. Are you keeping an eye on your expenditure?
Close down unprofitable shops, and make sure you fire the vendor. You still pay their wage even if the shop is closed.
Don't go mad on toilets / first aid etc. If you only have a small park with four rides then one toilet is plenty. You don't need first aid at all unless you're having major issues with vomit on the paths.
How many staff are you employing? One mechanic with some training is enough to look after 4 rides. Sack the ones you don't need they cost you money. Same goes for janitors - a couple of probably enough to keep on top of a small park. Don't bother with entertainers at all unless you have a major problem with guest happiness - they are an unnecessary expenditure.
Don't spend money on marketing unless you're really struggling with attendance but building rides should be enough to draw the crowds in this scenario especially if you build a second coaster. Only research if you really have to in order to get more rides to attract the crowds but do research the ATM as a priority. Happy guests that have spent all their cash will get more money and carry on spending rather than go home.
Hope that helps. Feel free to ask if you have any more questions.
Best wishes
Chris