I gave this 3 stars but really I would give the rooms 2 stars and the hotel grounds a 4. So I averaged it.
Stayed here and of the 3 rooms our party had the problems were:
Floors dirty.
Beds were more like cots. Thin, hard mattress on a metal frame.
Two sheets had 'pills' and would not stay on the mattress.
One room A/C units worked poorly.
One room had no hot water.
No place to sit other than the bed.
No shelves other than the ones inside closet.
One safe was broken.

As far as the hotel grounds, they were spectacular. Rooms had beautiful balconys with tables and chairs to sit and enjoy the trees/flowers/birds. Please note: lots of steps on brick walkways, definitely not for anyone with mobility issues.
We found a nice trail leading down into the jungle behind the hotel. Very lovely with a couple of swinging bridges and lots of assorted mosaic work that someone made. Would have been a highlight if not for the slight sewage smell near the bottom of the ravine.

We originally had a reservation at a cliff side hotel on the other side of town but realized immediately that it would make for too remote a stay in the area. Hotel Casitas Eclipse is located right on the main road into Manual Antonio park and is thus well positioned near restaurants and stuff. While trying to select an alternative accommodation we popped into many properties and can say with some authority that this one is a winner.

Laid out like a Greek island village, the property is multi-tiered with foliage and pathways and art and a pool. You could easily get lost in the labyrinthine design looking for your room. Trees grow thick and verdant between the rooms and buildings with enough space between them to see the ocean. An early morning wake up (thanks Howler Monkeys!) gifted us with a stunning view of the suns rays being strained between leafy branches into the thick, misty air.

Breakfast was passable and sufficient but not noteworthy.

A couple of tips; though the restaurant directly across the street lures diners in with the well placed husk of an actual US Military cargo plane (it was used in '71 to bring weapons in during iran/Contra), just look and move on; the food and service are like a Chili's without a manager. Just down the hill a few steps is another place, this one with a train car (same owners) that is way more convivial and serves up some great brick oven pizzas.

Also, when you visit the park you will be engaged (read harassed and lied to) by alleged park employees. The shirts may look official but they are NOT working for the park. They are trying to get you to spend about $42 USD per person on a guide. They will also cause you to park further from the gate than you probably need to so they can get you out of your car and make their pitch. If you wish to have a guide wait until you are at the gates of the park and hire an actual official guide there. Or, my advice; skip the guide completely. As you walk the paths in the park you will see plenty of people with guides and those guides will be pointing out wildlife and you just need to look where they're pointing. I think i just paid for your dinner, so you're welcome!

When one arrives and walks from reception to our rooms, the well landscaped and maintained outside appearance gives one the idea that we are in an upscale hotel.
Once we insert the key into the lock and try to open the door the questions begin.
We had two rooms, bath, and kitchenette. All looked like they belong to the 1970s.
It was clean, well made up and the beds were fine, but the room just looked old.
The two major problems were the A/C - old and super noisy.
As the power in the city kept going out, the A/C would stop and not come back on.
Maintenance arrived and fixed this problem.
The shower ran all night, no way to turn it off, we could not hear it due to the A/C noise.
Our concern with this facility and too many locations in Costa Rica was the lack of internet throughout the facility.
After full days, we have to do our writing in the evenings to submit our material to the Internet late at night.
The hotel had internet at the bar and reception. One required us to walk 150 and the other 250 yards, in the DARK.
With the power constantly going out, the bar router was often out. Reception had no clue on how to reset theirs.
We ended up being the tech support - troubleshooting, unplugging, resetting and rebooting.

During our trip across Costa Rica we spontaneously decided to spend one night in Manuel Antonio. We did not look for hotel before and we just selected Casitas Eclipse because of its nice location on top of a hill overlooking the ocean. The hotel was almost fully booked but we could get a nice, large room with view on the forest and close to the second swimming pool (really nice!). I do not know if we were particularly lucky or if it is a policy of the hotel, but we got a nice discount on the stay (ask for it, you might be lucky too!). The staff was friendly and helpful with some sightseeing tips. The restaurant of the hotel was quite disappointing, though: a pretty expensive Italian restaurant with a very poor service. Overall, Casitas Eclipse has a good price/quality ratio and is very convenient to explore Manuel Antonio.